Growth or profit?The Rule of 40 says yes.
One number tells an investor whether your growth is worth the money you're burning to get it. Add your YoY revenue growth and your profit margin; if they sum to 40 or more, you're allowed to trade one for the other. This shows you where you land, and which lever to pull if you're under the line.
Your numbers
Year-over-year revenue growth rate. ARR or revenue, your pick — just stay consistent. Negative if you're shrinking.
Free cash flow or EBITDA margin — profit ÷ revenue. Negative while you're burning, which is fine if growth covers it.
The verdict
Rule of 40 score
35
Status
Fail
5 short of 40.
Growth contribution
85.7%
Profit contribution
14.3%
How the score is built
Your score vs. the 40 line
You're 5 points under. Lift either growth or margin by that much to clear the line.
Reverse-solve · hit a target line
Margin needed
10.0%
Margin short by
5.0%
At 30% growth, hitting a 40 line needs a 10% profit margin — 5% more than you run today. Can't move margin that far? Make up the difference on the growth side instead — the rule lets you split it however you like.
Sensitivity · the growth–margin trade
Same line, different mixes
| Revenue growth | Margin to pass (40) | Margin for top quartile (50) |
|---|---|---|
| 0% | 40% | 50% |
| 15% | 25% | 35% |
| 30% | 10% | 20% |
| 45% | -5% | 5% |
| 60% | -20% | -10% |
| 90% | -50% | -40% |
| 120% | -80% | -70% |
Read it as a trade-off: every point of growth is a point of margin you don't need. At 30% growth you need 10% margin to pass — and 20% to reach top quartile. A negative requirement means the growth alone already clears the bar.
Your move
Under the line? The fix is usually in the funnel, not the spreadsheet.
Rule of 40 score 35 (30% growth + 5% margin) — below the 40 line.
A low Rule of 40 score almost always traces back to one leaky channel, one weak conversion step, or growth that's really just churn-replacement in disguise. Send me how you acquire and keep customers and I'll show you, free, which lever moves your score fastest — and you keep the plan whether or not we work together.
Plain English
Two numbers, one verdict.
The Rule of 40 says a healthy software business should have its revenue growth rate plus its profit margin add up to at least 40%. Grow 60% while burning 20% of revenue? You pass. Grow 10% at a 30% margin? You pass too. The rule doesn't care how you get to 40 — it cares that you got there.
That's the whole point: it lets you trade growth for profit and back again, as long as the sum holds. Early on you buy growth with margin (negative profit is fine when growth is high). Later you convert that growth into margin as expansion slows. A business that drops below the line is doing neither well — paying for growth it isn't getting.
It became the default heuristic for SaaS because it's hard to game with one quarter of accounting. To clear 40 you need real growth, real efficiency, or a credible mix of both. That's why investors reach for it before they reach for almost anything else — it compresses a whole income statement into a single, comparable number.
The formula
Rule of 40 = Revenue growth % + Profit margin %
Grow 30% YoY at a 5% margin → 30 + 5 = 35. That's below the line. Push growth to 38% at the same margin (or hold growth and lift margin to 12%) and you clear 40. Same destination, two different levers — that flexibility is the rule's entire value.
Where 40 sits
Forty is the pass mark; fifty is where the best companies live. Bessemer's framing maps a single score onto how investors actually read a software business — and what they'll pay for it:
| Band | Rule of 40 score | What it signals |
|---|---|---|
| Top quartile | 50+ | Efficient, fundable, premium multiple |
| Healthy | 40–49 | Above the line — investors lean in |
| Below the line | 0–39 | Workable, but spend or growth needs a fix |
| Value-destroying | Below 0 | Shrinking and burning at once |
Source: Bessemer Venture Partners — The Rule of 40 · 2024
You came back under 40. Which lever?
High growth, deep negative margin.
You're buying growth faster than it pays back. Don't kill the engine — tighten payback. Trim CAC, fix the worst-converting channel, and make sure the growth is net-new ARR, not churn-replacement.
Healthy margin, weak growth.
You've optimized for profit and starved the top line. The score won't move until growth does. Reinvest some of that margin into pipeline, expansion revenue, or a second motion before the market reprices you as ex-growth.
Both numbers are mediocre.
This is the dangerous quadrant — not growing, not earning. Pick one to win at this year. Usually growth, because a credible growth story buys you time that incremental margin never will.
Score is negative.
Revenue is shrinking and you're still burning. Stop the bleed first: get to flat or modestly positive cash flow, stabilize retention, then earn the right to spend on growth again.
Eight ways to move the score up
01Attack net revenue retention
Expansion from existing customers is the cheapest growth there is — it lifts the growth term without spending CAC, so both halves of the rule improve at once.
02Shorten CAC payback
Faster payback means each growth dollar returns to margin sooner. Cut payback from 18 to 12 months and the same growth costs you less margin.
03Cut the worst channel
There's almost always one acquisition channel quietly dragging blended efficiency. Reallocating its budget lifts margin with no hit to growth.
04Raise price on new logos
A pricing increase flows almost entirely to margin. Even a modest list-price lift on new customers moves the profit term within a quarter.
05Defend gross margin
Infra, support, and onboarding costs creep. A point of gross margin recovered is a point straight onto your Rule of 40 score.
06Kill zombie spend
Headcount and tooling that don't touch growth or retention are pure drag. Trim them to lift margin without slowing the top line.
07Lean into your best motion
If product-led converts at a fraction of sales-led CAC, feed it. Shifting mix toward your efficient motion raises both terms.
08Re-segment to your ICP
Your best-fit segment grows faster and churns less. Concentrating go-to-market there improves growth and retention simultaneously.
The vocabulary
- Rule of 40
- A heuristic that a healthy software company's revenue growth rate plus its profit margin should total at least 40%.
- Revenue growth (YoY)
- Year-over-year percentage change in revenue or ARR. The growth term in the rule.
- Profit margin
- Profit as a share of revenue — usually free cash flow or EBITDA margin. Can be negative for a high-growth burner.
- Free cash flow margin
- Operating cash flow minus capex, divided by revenue. The most conservative profit term to plug in.
- EBITDA margin
- Earnings before interest, taxes, depreciation, and amortization, as a share of revenue. A common, looser profit term.
- Net revenue retention
- Revenue kept and expanded from existing customers over a year. The single biggest lever on the score.
Rule of 40 questions, straight answers
40 or higher is the pass mark — at that point investors treat growth and margin as fairly traded. 50%+ is top-quartile and earns a premium valuation multiple. Below 40 isn't a death sentence, but it flags that either your growth or your spending discipline needs work. Negative means you're shrinking and burning at the same time.
Keep going
A calculator tells you what. A call tells you what to do about it.
Send me the account behind these numbers. I'll tell you straight where the money's leaking and what I'd fix first — free, and you keep it whether you hire me or not.