Before growth and profit get averaged into a success story
SaaS Rule of 40: Growth + Profit as a Health Tripwire
A slide that shows revenue climbing and never mentions the profit (or the loss) that paid for it is not validation. The Rule of 40 asks a smaller, honester question: did this period’s growth rate plus profit margin clear a bar you wrote first? Matching it is a decision signal — not a forecast that you will succeed, and not a substitute for naming the weakest demand or retention assumption first.
Last updated: October 16, 2026
Direct answer
What is the Rule of 40 — and why write the tripwire first?
The Rule of 40 says a healthy scaled software/SaaS company should have revenue growth rate plus profit margin ≥ 40%. Example: 20% growth + 20% profit, or 50% growth + (−10%) profit, both hit 40. Matching or missing a pre-written tripwire is a decision signal — not a prediction that you will succeed.
Key takeaways
What to remember
- Rule of 40 = Growth rate (%) + Profit margin (%). Brad Feld (3 February 2015) popularized a late-stage investor’s 40% rule from a board meeting. His examples, used as written: 20%+20%; 40%+0%; 50%+(−10%); beating 40 is “awesome.” Prefer YoY MRR growth; prefer EBITDA as the profit baseline, then back-test. State the choice before you score. Do not mix definitions mid-comparison.
- At scale, not at seed. Feld’s investor framing assumed at least ~$50 million in revenue; he also notes it correlates with his own SaaS product-market-fit writing around ~$1 million MRR. Do not paste ≥40 onto a pre-revenue or seed sitting and call it a scorecard. For high-burn early companies, Bessemer prefers burn multiple over forcing this math.
- Bain (20 December 2018) researched 124 publicly traded software companies: 40% outperformed the Rule of 40 in a single year (2017). Of 86 companies from 2013–2017, 25% outperformed for three or more years; only 16% for all five years (M&A-adjusted). Bain’s study, not a universal law. Companies that outperform had EV/revenue valuations about double those below the line, and returns as much as ~15% higher than the S&P 500 — Bain’s claim, attributed.
- Bessemer’s Rule of X (Deeter & Bondy, 2 January 2024) argues equal weight of growth and profit is flawed for late-stage cloud approaching FCF+. Rule of X = (Growth rate × Multiplier) + FCF margin. Private ~2x; public ~2–3x when growth is efficient. Same 45% Rule of 40 can be 75% or 60% under a 2x Rule of X depending on mix. Late-2023 BVP Cloud Index averages (Bessemer’s dataset): Rule of 40 ~31%; Rule of X ~50%. Top decile: ~48% and ~80% (with a ~2.3x multiplier in that sitting).
- Write signal + threshold (e.g. ≥40) + which growth definition + which profit definition + calendar window + named action (invest for growth / hold / cut burn / raise efficiency) before you measure. Prefer a multi-period trend over one heroic year. A Yibud score is not Rule of 40 and not a success prediction.
Why it matters
Why adding growth to profit is a health sitting — at the scale it was written for
Founders steal a late-stage board habit and run it on a twelve-person company. Three published sources are useful here as instruments, not as personal odds: Feld on the formula and the scale caveat, Bain on how rare multi-year consistency is among public software companies, and Bessemer on why equal weight of growth and free cash flow misleads once you are near FCF+.
Feld’s board-meeting rule — at scale, then correlated near $1M MRR
Feld (3 February 2015) heard a late-stage investor describe the 40% rule for a healthy software company, including business SaaS, at a board meeting. These are companies at scale — assume at least $50 million in revenue — though Feld notes it correlates with his own SaaS product-market-fit writing once you hit about $1 million of MRR. The punch line: you can lose money if you are growing faster, but the sitting is still a balance, not a trophy growth rate.
Bain: beating 40 once is common; beating it for years is not
Bain (Depeyrot & Heap, 20 December 2018) uses EBITDA and treats the Rule of 40 as a high-level gauge of the growth-versus-profit trade-off. Young companies often beat the mark with rapid growth; older, slower-growth companies have to improve margins. Beating the rule in a single year is admirable. Keeping the balance year after year is the harder sitting — Bain’s 40% / 25% / 16% consistency numbers, labeled as Bain’s study, not a law of nature.
Bessemer: equal weight is the wrong late-stage trade-off
Deeter & Bondy (2 January 2024) argue that assigning equal weight to growth and profitability is flawed for late-stage cloud companies approaching or achieving FCF positivity. A 1% increase in growth can compound; a 1% increase in FCF margin is closer to linear. Their Rule of X puts a multiplier on growth and uses FCF margin. That is a different instrument from Feld’s Rule of 40. Do not flatten them into one homemade grade table.
The five terms
Growth, profit, Rule of 40, Rule of X, tripwire
These five fields are the instrument. If any one is fuzzy, the number is a slide, not a tripwire. This page does not publish a grade table beyond the sources. Use Feld’s examples, Bain’s consistency stats, and Bessemer’s Rule of X math as labeled, then write your own bar.
Growth rate — say which one, then keep it
Feld prefers year-over-year growth of monthly MRR as the easiest / cleanest baseline. You can also look at GAAP revenue, but check MRR too so one-time services mix does not fake the growth rate. Back-test with YoY growth of gross margin so COGS is scaling with revenue. Some people will use ARR, or strange year-on-year-by-month permutations. Name the definition. Do not switch it after the report.
Profit margin — EBITDA, FCF, or something else; pick before scoring
Analysts differ. Feld lists EBITDA, operating income, net income, free cash flow, cash flow, and “something else,” then prefers EBITDA as the baseline and back-tests the others. Bain uses EBITDA, a publicly available metric that excludes taxes and accounting-policy effects; some have proposed FCF, EBIT, or net income. Bessemer’s Rule of X discussion uses FCF margin. State the choice before you score. Do not mix EBITDA and FCF in the same comparison.
Rule of 40 — growth % plus profit %
Feld: growth rate plus profit should add up to 40%. 20% growth with 20% profit; 40% growth with 0% profit; 50% growth with a 10% loss. Better than 40 is “awesome.” Bain restates it as combined growth rate and profit margin should exceed 40%. This page uses ≥40 as the tripwire threshold founders write, then honor. It is a balance gate. It does not prove you will succeed.
Rule of X — growth, weighted, plus FCF margin
Bessemer: Rule of X = (Growth rate × Multiplier) + FCF margin. Private companies ~2x on growth; public ~2–3x when the growth is efficient. The multiplier floats; they treat ~2x as a conservative private-company base. This is not Feld’s Rule of 40 with a new nickname. It is a different sitting with a different profit definition (FCF) and a weight on growth.
The tripwire — written before you measure
Signal + threshold + which growth definition + which profit definition + calendar window + named action (invest for growth / hold / cut burn / raise efficiency). Write it on a dated page before the first period report. A kinder bar after the results is a recap, not a tripwire. Matching the bar is a decision aid. It does not prove you will succeed.
Feld’s formula and examples
20+20, 40+0, 50+(−10) — plus the scale caveat
Feld wrote the formula and the examples on 3 February 2015. Use them as he wrote them. Do not paste a later five-tier grade chart onto this page and call it Feld’s. Do not invent First Round Level Rule-of-40 bands — First Round’s efficiency list names magic number, CAC payback, NRR, gross margin, and burn multiple, not Rule of 40 thresholds.
The formula: add the two percentages
Growth rate + profit = 40%. Feld prefers YoY MRR growth as the cleanest growth number, then back-tests GAAP revenue and YoY gross-margin growth so COGS is not silently eating the story. For profit he prefers EBITDA as the baseline, then back-tests operating income, net income, free cash flow, and cash flow. If you run your own infrastructure, those lines diverge because of equipment, debt, or leases. Be precise about which number you are using.
The examples: 20/20, 40/0, 50/−10
If you are growing at 20%, you should be generating a profit of 20%. Growing at 40%, 0% profit. Growing at 50%, you can lose 10%. Doing better than the 40% rule is “awesome.” Those are Feld’s four sittings. This page does not invent a fifth band or a letter grade.
A 40% growth “point of happiness” — Feld’s line, not a law
Feld writes that the punch line is you can lose money if you are growing faster, and that the minimum “point of happiness” is 40% annual growth. Keep that attributed to Feld. It is how he framed the growth side of the sitting, not a universal seed-stage law, and not a reason to ignore the profit side of the sum.
Scale caveat, from the same post: the late-stage investor’s framing assumed at least ~$50 million in revenue. Feld also notes the rule correlates with his Illusion of Product/Market Fit writing once you hit about $1 million of MRR. Sub-scale companies often say they can get profitable right away if they slow growth — often true, Feld writes, but then you stay sub-scale longer with a 20% growth / 20% profit mix. That is a capital-allocation choice, not a seed validation score.
VC-backed path note, still Feld: if you are going to raise venture money, get focused on the T2D3 approach to get to scale, then start focusing on the 40% rule. T2D3 is Battery / Agrawal’s growth path, which Feld points at; this page does not invent T2D3 numbers. Rule of 40 is the later sitting, after scale, not the first instrument on a landing-page test.
Bain’s consistency sitting
40% in one year, 25% for three, 16% for five — Bain’s study
Bain researched publicly traded software companies. The numbers below are Bain’s, from 20 December 2018, labeled as such. They are not a personal odds table and not a law you must hit next quarter. Use them as a vocabulary for “how rare is multi-year consistency,” then write your own tripwire for the periods you can actually measure.
| Window (Bain) | What they found | How to label it |
|---|---|---|
| Single year (2017) | 40% of 124 publicly traded software companies outperformed the Rule of 40. | Bain, “Hacking Software’s Rule of 40,” 20 December 2018. Bain’s study, not a universal law. |
| Three or more years (2013–2017) | Of 86 companies researched from 2013 to 2017, 25% outperformed for three or more years. | Same Bain study. M&A-adjusted. Not a seed-stage forecast. |
| All five years (2013–2017) | Only 16% outperformed for all five years, adjusted for mergers and acquisitions. | Same Bain study. Consistency is the scarce sitting, not a single heroic year. |
| Valuation and returns (Bain’s claim) | Companies that outperform have valuations (EV/revenue) about double those below the line, and returns as much as ~15% higher than the S&P 500. | Bain’s claim, attributed. Not a promise that matching 40 will double your multiple. |
Three Bain paths to beat the rule, labeled as Bain’s: strong growth (revenue growth above 30%); balanced (10–30%); profitability-led (below 10% growth, with 18% of the five-year outperformers in that bucket). Young companies often beat via growth; older, slow-growth companies must improve margins. This page does not invent a fourth path.
Scope note, from the same essay: Bain uses EBITDA. Analysts have differed — most use EBITDA; some have proposed free cash flow, EBIT, or net income. If your tripwire uses FCF because you are reading Bessemer, say so. Do not compare an EBITDA Rule of 40 to a FCF Rule of 40 and call them the same sitting.
Bessemer’s Rule of X
Weight growth, use FCF, and do not starve the compounding side
Deeter & Bondy (2 January 2024) treat Rule of 40 as a heuristic Bessemer helped popularize — the sum of revenue growth and profit margin should equal 40%+ — then argue the equal-weight math is the wrong late-stage cloud trade-off. Use their numbers as Bessemer’s, from late 2023, not as a 2026 industry median and not as a seed law.
The formula: (Growth × multiplier) + FCF margin
Rule of X = (Growth rate × Multiplier) + FCF margin. Bessemer’s recommended multiplier: about 2x for late-stage private businesses; about 2–3x for public companies when growth is efficient. The “X” floats with market conditions and stage. Do not treat 2x as a constant of nature. Do not swap FCF for EBITDA mid-sentence and keep calling it Rule of X.
The 30/15 example — same Rule of 40, different Rule of X
Bessemer’s hypothetical: 30% growth and 15% profit / FCF margin → Rule of 40 = 45%. Rule of X at a 2x multiplier = 75% (30% × 2 + 15%). Flip the mix to 15% growth and 30% FCF: still 45% on Rule of 40, lower on Rule of X. All else equal, Bessemer says the growth-heavier mix should be valued more highly. That is their composition point, not a Yibud grade table.
Late-2023 BVP Cloud Index — Bessemer’s dataset
As of late 2023, Bessemer writes, the average Rule of 40 for the BVP Cloud Index was ~31% and the average Rule of X ~50% (medians similar to means). Top-decile public cloud: Rule of 40 ~48% (top few 50%+); Rule of X ~80% average, based on a 2.3x multiplier (top few ~90%+). Labeled as Bessemer’s Cloud Index sitting, not a law for a fourteen-person company.
Do not starve growth for FCF — still Bessemer
A margin increase has a linear impact on value, they argue; a growth-rate increase can compound. In a public-cloud sitting they cite, a 1% increase in growth rate had 2.3x the positive impact on valuation multiple versus a 1% increase in FCF margin. Keep the attribution. It is a late-stage valuation argument, not permission to burn without a tripwire.
Early-stage caveat, still Bessemer: Rule of X is less relevant for earlier-stage private businesses growing very fast and burning very hard for extended periods. For an early-stage venture/growth investment with negative FCF, they still think in terms of an attractive burn multiple (ideally ~1x–1.5x in their framing). That instrument lives on the burn-multiple page. Do not force Rule of X onto a pre-revenue spreadsheet.
Bessemer is explicit that Rule of X is a guide more than a rule, and that it cannot be used in a vacuum — market size, unit economics, retention, and the rest still matter. This page does not pretend the multiplier is a validation score.
How to run it
How to run a Rule of 40 tripwire without faking scale
This is Yibud’s suggested sequence, not a Feld checklist, not a Bain law, and not a Bessemer mandate. Honor the tripwire you wrote before the first report. If you cannot name the decision the number would change, you are building a slide.
- 1
Write the tripwire before you look
Signal is Rule of 40 (and, if you use it, Rule of X) plus its direction versus prior periods. Threshold is the miss / pass line you will honor — Feld’s ≥40 is the classic gate. Name which growth definition (YoY MRR, GAAP revenue, ARR) and which profit definition (EBITDA, FCF, other). Window is the calendar close. Action is invest for growth, hold, cut burn, or raise efficiency. Do not rewrite the bar after the report.
- 2
Pick one growth definition and one profit definition. Say them out loud.
Feld’s default pair: YoY MRR growth + EBITDA, then back-test. Bain’s public-company pair: growth + EBITDA. Bessemer’s Rule of X pair: growth + FCF margin, with a stated multiplier. If you mix EBITDA into a Rule of X sitting, you are no longer running Bessemer’s instrument. Write the pair on the dated page.
- 3
Compute the sum. Optionally compute Rule of X on FCF, separately.
Rule of 40 is addition, not a ratio. 28% growth and 8% EBITDA margin is 36 — a miss against a ≥40 bar you wrote. If you also run Rule of X, use FCF margin and a stated multiplier, and keep that number in its own column. Do not average the two sittings into a homemade “health score.”
- 4
Prefer the trend across periods over one heroic year
Bain’s consistency lesson: 40% of their 124 public software companies cleared the rule in 2017; 16% of 86 cleared it for all five years from 2013–2017. One cheap year after a brutal one is not the story. Two or three periods on the same definitions tell you if the mix is improving or collapsing. Headline revenue can still rise while Rule of 40 falls.
- 5
Honor the action. If you are still early, use a different instrument.
If the window closes and you missed the bar you wrote, do the thing you named — hold, cut burn, raise efficiency, or keep testing demand. Do not invent next year’s growth so the spreadsheet prints 40. Pre-revenue and pre-$1M MRR sittings belong on demand tests or burn multiple, not here. Company cash versus net new ARR is the burn-multiple page. S&M → incremental revenue is Magic Number. Months to recover CAC is payback. This sitting is growth + profit.
What you leave with
The Rule of 40 tripwire (copy this)
If the sitting produced a sum and no dated action, you did not finish. Fill the brackets. Leave nothing as “balance is fine,” “soon,” or “we’ll know it when the round happens.”
The fill-in contract
Product: [name]. Period: [start–end]. Hypothesis this number can falsify: [we can keep investing for growth because the growth+profit mix clears our bar]. Growth definition: [YoY MRR / GAAP revenue / ARR]. Profit definition: [EBITDA / FCF / other — pick one]. Growth %: [ ]. Profit %: [ ]. Signal: [Rule of 40 = growth % + profit %, and/or change vs last period]. Optional Rule of X: [growth % × multiplier + FCF margin; multiplier = 2x private / stated]. Threshold: [e.g. honor a miss if Rule of 40 is below 40 — Yibud template using Feld’s 40% rule, not a seed law]. Window: books close [date], written before the first report. Action if miss: [invest for growth / hold / cut burn / raise efficiency]. Compare the next period on the same definitions. A Yibud score does not fire this line.
The “below 40” line is Yibud’s suggested template for a scaled-company balance sitting, taken from Feld’s 40% rule — not Bain’s 16% five-year consistency treated as a personal target, and not Bessemer’s top-decile ~48% pasted onto a twelve-person company. Rewrite the threshold before you measure if you have a reason. Do not rewrite it after.
Example tripwire (Yibud’s suggested template, not a law)
If, for FY2026, Rule of 40 (YoY MRR growth + EBITDA margin) is below 40 when we close the books on 31 December → we do not raise a growth-at-all-costs round in Q1; we hold burn and name the weakest retention assumption. Do not invent next-year growth to create a friendlier sum. Do not swap FCF in after the close without saying you changed the profit definition.
A 42 on a single lucky year is still one year. A Yibud report score does not fire this tripwire. If you are pre-$1M MRR, this template is the wrong first instrument — use burn multiple or a demand test instead.
The fork
When to use a Rule of 40 tripwire — and when not to
Rule of 40 is the wrong first instrument when there is no revenue yet, you are still below Feld’s scale caveat, or you are running consumer ads-only tests to see if anyone clicks. It is the right instrument when subscription revenue already exists at meaningful scale and you are deciding whether to keep buying growth or to raise the profit side of the mix.
Use it when you have a named growth rate, a named profit line, and a capital-allocation decision
You can name YoY MRR (or GAAP revenue / ARR) and a profit definition (EBITDA or FCF — pick one) for a closed period. You are about to raise a growth round, slow hiring, or tell yourself “growth covers the losses.” That is when a dated balance line earns its keep. Prefer two or three periods so you can see direction, not one trophy year. Optional: run Rule of X in a second column with FCF and a stated multiplier.
Do not start here when you are pre-revenue, pre-$1M MRR, or still need first money, reach, or a who-filter
No revenue yet? There is no growth rate that means what Feld meant. Do not invent a forecast numerator. Still below about $1 million MRR, and nowhere near $50 million revenue? Feld’s investor framing was at scale. Consumer ads-only early tests that have not produced subscription economics belong on reach or willingness-to-pay pages, not here. High-burn early companies: Bessemer prefers burn multiple (~1–1.5x in their framing) over forcing Rule of X. Months to recover CAC on one channel is a different instrument. Still writing Stop / Pivot / Continue? Those are the decision contracts. This page supplies one company-level balance number those contracts can later read. It does not replace them.
Worked example
One B2B SaaS year you can copy (illustrative — fictional)
The year below is illustrative. Names, product, and counts are invented so you can see the arithmetic. It is not a study, not an industry benchmark, and not a Yibud report. Copy the method, not the numbers.
The promise, written before the year closes
Illustrative names: founder Priya Shah at Northline, an operations tool for mid-market B2B teams. Subscription revenue exists. EBITDA exists. The tempting trophy is a year-end slide that shows revenue up and never adds the margin. The tripwire is written first, on 2 January: honor a miss if FY Rule of 40 (YoY MRR growth + EBITDA margin) is below 40 before we raise a growth round — Yibud’s suggested template from Feld’s 40% rule, not Bessemer’s top-decile ~48% pasted onto a sixteen-person company, and not a claim that Northline is a $50 million-revenue business. ARR here is about $1.4 million — closer to Feld’s $1 million MRR correlation note than to the late-stage $50 million frame. That caveat stays on the page.
The inputs, kept honest
Year-ago MRR = $90,000. This-year MRR = $117,000. YoY MRR growth = ($117,000 − $90,000) ÷ $90,000 = 30%. Annualized revenue ≈ $1.404 million. FY EBITDA = −$140,400. EBITDA margin = −10%. Rule of 40 = 30% + (−10%) = 20. Last year on the same definitions was 24. Headline revenue still rose. The sum slipped. Feld’s examples: 20 is not 20+20, not 40+0, and not 50+(−10). It is a miss against a ≥40 bar. Separately, FCF margin this year = −12%. Rule of X at a 2x private multiplier = 30% × 2 + (−12%) = 48. Different profit definition. Different sitting. Do not average 20 and 48.
The tripwire, written 2 January
Signal: FY Rule of 40 (YoY MRR + EBITDA) and its change versus last year. Threshold: honor a miss if the number is below 40 before we raise a growth round. Window: books close 31 December. Action if miss: do not raise a growth-at-all-costs round in Q1; hold burn; name the weakest retention assumption. A Yibud score does not fire this line. The 40 bar is Yibud’s suggested template for a balance sitting, not Bain’s 16% five-year public-company consistency treated as a personal target, and not permission to ignore Feld’s scale caveat.
What a miss looks like — and what must not happen
Illustrative close: 20 is below 40. 31 December is a miss on the bar they wrote. Hold the growth round. Do not swap FCF in after the close, print Rule of X = 48, and call the debate settled — that is mixing profit definitions. Do not forecast next year’s 50% growth to invent a friendlier sum. Do not treat Bain’s “40% beat it in 2017” as permission to ignore a miss you wrote. Do not treat 20 as proof the startup will fail, either. Keep next year on the same YoY MRR + EBITDA pair. If they also want Rule of X, it stays in its own FCF column.
Write the tripwire before the first report. If the window closes and the mix misses the bar you wrote, honor the action. If it cleared the bar, continue to the next cheapest test — usually the next period on the same definitions, or a kill/pivot contract that now has a number to read. The method is the dated page, not the revenue headline. Neither 20 nor 42 predicts success.
Not the same page
Rule of 40 vs Magic Number, burn multiple, CAC payback, vanity metrics, WTP, Ellis, NPS, failure rates, market size, Yibud scores, and decision contracts
Several Yibud pages sit next to this one. Mixing them up turns a sales-efficiency ratio, a company cash multiple, a channel payback month, a waitlist, a recommend score, or a mid-band engine number into “growth plus profit is healthy.”
SaaS Magic Number — S&M → incremental revenue, not this growth+profit sum
That page asks how efficiently prior-period sales and marketing spend turned into incremental subscription revenue (often with a one-quarter lag). This page asks whether growth rate plus profit margin cleared a bar you wrote. A 1.2 Magic Number does not tell you the company is above 40 on growth+EBITDA. A 42 Rule of 40 does not tell you last quarter’s S&M paid for itself. Keep the instruments on separate pages.
SaaS Magic Number →Burn multiple — company cash vs net new ARR, not this growth+margin sum
That page asks how much company cash you burned, in a period, per dollar of net new ARR (Net Burn ÷ Net New ARR). This page is addition: growth % + profit %. Bessemer even prefers burn multiple (~1–1.5x in their framing) for high-burn early companies instead of forcing Rule of X. A 2x burn multiple does not tell you Rule of 40. A 20 Rule of 40 does not tell you the company is burning too much cash per new ARR. Keep the instruments on separate pages.
Burn multiple for startups →CAC payback — months to recover a cohort’s acquisition cost, not this sum
That page asks how many months of contribution recover fully-loaded CAC for a named cohort or channel. This page is a company-level growth-plus-profit sitting. Payback can look fine on one cheap organic vintage while Rule of 40 is 20. A 42 Rule of 40 does not tell you LinkedIn ads pay back. Keep the instruments on separate pages.
CAC payback for startups →Vanity metrics — hygiene class, not this balance tripwire
That page is the sorting hat: hits, cumulative signups, and waitlist size feel like progress and do not tell you what to do next. This page is one specific actionable balance number. A pretty Rule of 40 chart with no tripwire can still be vanity. A waitlist is not a profit margin.
Vanity metrics for startups →Willingness to pay — first money on a deal, not growth plus profit
That page is a deposit, pre-order, paid concierge, or priced checkout as proof that money moved once. Rule of 40 needs a named growth rate and a named profit line on a closed period. A paid first month with a 12 Rule of 40 can still miss the tripwire you wrote — and at that stage you probably should not be running this sitting yet.
Willingness-to-pay test →Sean Ellis PMF survey — disappointment among current users
That page’s signal is the percent of recent real users who would be very disappointed if the product disappeared. Feld’s ≥40 gate is a scaled-company balance sitting, not Ellis’s question. Do not treat “very disappointed” as Rule of 40, and do not treat a 42 Rule of 40 as Ellis’s bar.
Product-market fit survey →NPS — one recommend-intent score
That page is stated recommendation intent among people who already used you. A high NPS does not raise Rule of 40. A 42 Rule of 40 does not mean people would recommend you. Keep the instruments on separate pages.
NPS for early-stage startups →Startup failure rate — population frequencies, not the math
That page is what the failure data says at population level — BLS establishment survival, venture-backed “failure” as reported, and why a base rate is not your fate. This page teaches one growth-plus-profit instrument those tables do not compute. It does not invent a “percent of startups that die from a low Rule of 40.”
What percentage of startups fail →Market sizing — TAM/SAM/SOM, not growth plus profit
That page names buyers you can reach and a revenue story. A large SOM does not make a 20 Rule of 40 healthy. A 42 Rule of 40 does not size a market. Do not file a TAM slide under Rule of 40.
Startup market sizing →Yibud scores — not Rule of 40, and not a success prediction
The validation-score and score-calculator pages explain Startup MRI numbers from a deterministic rule engine on a one-line idea plus five questions. Those scores point at the weakest assumption to test next. They are not Rule of 40. They are not Rule of X. They are not Magic Number, burn multiple, or CAC payback. Do not read a mid-band monetization score as “growth plus profit is healthy,” and do not read a 42 Rule of 40 as a Yibud GO.
Kill, pivot, critical assumption, decision — contracts that can read this number
Those pages write Stop, rewrite one dimension, name the one claim that would kill the idea if false, or decide after evidence. This page can supply the company-level balance instrument those contracts later read: a dated Rule of 40 against a bar you wrote first. A revenue headline with no profit definition cannot fire a kill line honestly.
Where Yibud fits
Neither Rule of 40 nor a Yibud score predicts success
Yibud is a free, no-signup startup idea validator. Scores come from a deterministic rule engine, not from a language model guessing success. Optional AI text, when it is used, only polishes prose. It does not invent the number. A Startup MRI report can name a weak monetization or distribution assumption, then a Day-7 Continue / Refine / Re-test / Stop signal. The score is a flashlight on the weakest assumption to test next — not Rule of 40, not Rule of X, not Magic Number, not burn multiple, not CAC payback, not a forecast. Rule of 40 work sits next to that assumption: write the tripwire, do not hope a rising revenue slide means the growth-plus-profit mix is healthy. If you already have a report, start with the named assumption, not the overall score. Then run the period yourself. The method on this page stands alone if you never open the analyzer.
Analyze my idea →Common mistakes
What usually wastes a Rule of 40 week
Treating ≥40 as proof you will succeed
A Rule of 40 at or above 40 means that period cleared Feld’s 40% gate — or cleared a bar you wrote. It does not mean the startup will succeed. It is not Ellis’s very-disappointed question, not a deposit, and not a Yibud GO. Bain’s public-company outperformers still had to keep the mix year after year. Neither Rule of 40 nor a Yibud report score predicts success.
Applying the sitting to seed without Feld’s scale caveat
Feld’s investor framing assumed at least ~$50 million in revenue. He correlates it with his own SaaS PMF writing around ~$1 million MRR. Pre-revenue, there is no honest growth-plus-profit sum. High-burn early companies: Bessemer prefers burn multiple over forcing Rule of X. Do not paste 40 onto a landing-page week and call it research.
Mixing EBITDA and FCF mid-comparison
Feld prefers EBITDA then back-tests. Bain uses EBITDA. Bessemer’s Rule of X uses FCF margin. If you compute Rule of 40 on EBITDA and Rule of X on the same EBITDA line, you are no longer running Bessemer’s instrument. State the profit definition on the dated page. Keep it.
Optimizing one heroic year
Bain: 40% of 124 public software companies beat the rule in 2017; only 16% of 86 beat it for all five years from 2013–2017 (M&A-adjusted). One year that prints 42 after a year that printed 12 is not the consistency sitting. Direction of travel on the same definitions is the story, not the trophy year.
Starving growth for FCF when Rule of X says growth still compounds
Bessemer’s late-stage argument: equal weight is flawed once you are near FCF+; a growth increase can compound while a margin increase is closer to linear. Cutting efficient growth to decorate FCF can lower Rule of X even when Rule of 40 stays flat. Keep that attributed to Bessemer, for late-stage cloud, with a stated multiplier. It is not a license for seed companies to ignore burn. And it is not a First Round Level — they do not publish Rule of 40 bands.
Sources
Where these ideas come from
- Brad Feld, “The Rule of 40% For a Healthy SaaS Company,” 3 February 2015 — Used for the late-stage investor 40% rule heard at a board meeting; scale of at least ~$50 million in revenue and Feld’s correlation note around ~$1 million MRR; growth rate + profit ≥ 40%; examples 20%+20%, 40%+0%, 50%+(−10%), and beating 40 is “awesome”; preference for YoY MRR growth plus a GAAP-revenue check and a YoY gross-margin back-test; preference for EBITDA as the profit baseline then back-testing other percentages; the 40% annual-growth “point of happiness”; the sub-scale “we can get profitable if we slow down” warning; and T2D3 then Rule of 40 for a VC-backed path. This page does not invent further grade tiers.
- Thierry Depeyrot & Simon Heap / Bain & Company, “Hacking Software’s Rule of 40,” 20 December 2018 — Used for EBITDA as Bain’s profitability metric; the single-year vs multi-year consistency sitting (40% of 124 public software companies in 2017; 25% of 86 for three or more years from 2013–2017; 16% for all five years, M&A-adjusted); EV/revenue valuations about double those below the line; returns as much as ~15% higher than the S&P 500 (Bain’s claim); young companies often beating via growth and older companies needing margin improvement; and the three paths (strong growth >30%, balanced 10–30%, profitability-led <10%). Labeled as Bain’s study, not a universal law.
- Byron Deeter & Sam Bondy / Bessemer Venture Partners, “The Rule of X,” 2 January 2024 — Used for the critique that equal weight of growth and profit is flawed for late-stage cloud approaching FCF+; Rule of X = (Growth rate × Multiplier) + FCF margin; private ~2x and public ~2–3x when growth is efficient; the 30% growth + 15% FCF example (Rule of 40 = 45%; Rule of X at 2x = 75%) and the flipped-mix valuation point; late-2023 BVP Cloud Index averages (Rule of 40 ~31%; Rule of X ~50%) and top-decile (~48% and ~80% with a ~2.3x multiplier); the warning not to starve growth for FCF; and the early-stage preference for burn multiple (~1x–1.5x) over forcing Rule of X. Labeled as Bessemer’s dataset and argument, not a seed law.
In one paragraph
Summary you can quote
The Rule of 40 says a healthy scaled software/SaaS company should have revenue growth rate plus profit margin ≥ 40%. Feld (3 February 2015): a late-stage investor’s board-meeting rule; assume at least ~$50 million in revenue, with a correlation note around ~$1 million MRR; 20%+20%, 40%+0%, 50%+(−10%); prefer YoY MRR growth and EBITDA as baseline, then back-test; beating 40 is “awesome”; 40% annual growth as his “point of happiness.” Bain (20 December 2018): EBITDA; 40% of 124 public software companies beat it in 2017; 25% of 86 for three or more years, 16% for all five (2013–2017, M&A-adjusted); EV/revenue about double; returns as much as ~15% vs the S&P 500; three paths (>30% / 10–30% / <10%). Bessemer (2 January 2024): Rule of X = (Growth × multiplier) + FCF margin; private ~2x, public ~2–3x; 30/15 → 45% vs 75%; late-2023 Cloud Index ~31% / ~50%, top decile ~48% / ~80%; early-stage prefer burn multiple. Write signal + threshold + definitions + window + action before you measure. Prefer the trend. Matching the gate is a decision signal. Neither Rule of 40 nor a Yibud score predicts success.
FAQ
Questions founders actually ask
What is the SaaS Rule of 40?
A company-level balance sitting: revenue growth rate plus profit margin should add up to at least 40%. Feld’s examples: 20% growth + 20% profit; 40% + 0%; 50% + (−10%). It is a health / capital-allocation tripwire for scaled software/SaaS, not a success score. Write the bar before you measure.
What is a good Rule of 40 for a startup?
This page does not publish a universal “good” grade table beyond the sources. Feld (3 February 2015): ≥40, with 20/20, 40/0, 50/−10 as examples, written for companies at scale (~$50 million revenue in the investor framing; Feld also notes ~$1 million MRR). Bain (20 December 2018), public software: 40% beat it in one year (2017); 16% of 86 for all five years 2013–2017. Bessemer late-2023 BVP Cloud Index: average ~31%; top decile ~48%. Write your own tripwire. Do not invent First Round Level Rule-of-40 bands — they do not publish them.
How is Rule of 40 different from Magic Number, burn multiple, and CAC payback?
Magic Number is how efficiently prior-period S&M turned into incremental subscription revenue. Burn multiple is company-level Net Burn ÷ Net New ARR in a period. CAC payback is how many months of contribution recover fully-loaded acquisition cost for a named cohort or channel. Rule of 40 is growth % + profit %. They answer different decisions. Use Magic Number for S&M efficiency, burn multiple for cash versus new ARR (Bessemer’s early-stage preference), payback for the channel, this page for the growth-plus-profit mix.
Should I use Rule of 40 before $1 million MRR, or at seed?
Not as a scorecard. Feld’s investor framing assumed at least ~$50 million in revenue; he correlates the rule with his SaaS PMF writing around ~$1 million MRR. Pre-revenue, the sum does not mean what they meant. Bessemer: for high-burn early companies, prefer burn multiple (~1–1.5x in their framing) over forcing Rule of X. Still testing whether anyone will pay? Use the willingness-to-pay page first.
Is a Yibud score the same as Rule of 40? Does it predict success?
No and no. Yibud scores come from a deterministic rule engine on your idea inputs. They point at the weakest assumption to test next. They are not Rule of 40, not Rule of X, not Magic Number, not burn multiple, not CAC payback, and not a forecast. Neither a Rule of 40 pass nor a Yibud report score predicts success. You do not need an account to use this page.
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