Khaled Azar 
The most overused metric in SaaS M&A is costing founders real money at exit.
The Rule of 40 is the most overused metric in SaaS M&A. Growth rate plus profit margin equals 40 or higher, and your company is “healthy.” Except in practice, we’ve seen companies score 55 on the Rule of 40 and still receive mediocre offers — and companies score 28 and command premium multiples. The number alone tells buyers almost nothing about what your business is actually worth.
If you’re a SaaS founder preparing for an exit, chasing a Rule of 40 score could lead you to optimize for the wrong things. Here’s what actually drives multiples in 2026 — and why the Rule of 40 keeps misleading sellers.
What the Rule of 40 Gets Right (and Where It Stops)
The formula is elegant. The problem is what it ignores.
The formula is simple: ARR growth rate + EBITDA margin >= 40%. A company growing 30% with 15% EBITDA margins hits 45. One growing 10% with 35% margins also hits 45. The Rule of 40 treats both as equivalent.
They are not.
According to SaaS Capital’s 2025 annual survey, Rule of 40 scores for private SaaS companies have declined across nearly every ARR bracket and funding type over the past two years. The primary driver? Falling revenue growth rates. The metric that was supposed to signal health is getting worse industry-wide — yet deals are still closing at strong multiples for companies with the right underlying fundamentals.
The Rule of 40 is declining industry-wide, yet strong deals still close. The composite score masks what actually matters to buyers: the quality and durability of your growth.
The Metric Buyers Actually Care About: Growth Quality
Buyers don’t pay for a score. They pay for compounding economics.
In our practice at Livmo, we’ve worked on 100+ transactions across the lower middle market. The pattern is consistent: buyers pay premiums for the quality of growth, not the quantity of growth-plus-profit.
Here’s what that means in practice:
- Net Revenue Retention (NRR) above 110% — This tells a buyer your existing customers are spending more over time. A company with 90% NRR growing 40% is on a treadmill. A company with 120% NRR growing 25% has compounding economics. Buyers know the difference. SaaS businesses with NRR above 120% typically command 8-12x ARR multiples in current exit transactions.
- Revenue concentration below 20% — If your top customer is 30% of revenue, your Rule of 40 score is irrelevant. That’s a customer concentration problem that kills deals.
- Growth trajectory, not snapshot — A company that grew 50% last year and is trending to 25% this year looks worse than one that grew 20% last year and is tracking to 30%. Deceleration terrifies buyers. Acceleration excites them.
- Gross margin structure — SaaS gross margins of 75%+ signal a real software business. Margins below 65% raise questions about services dependency and scalability.
Net Revenue Retention is the single strongest predictor of premium valuations in current SaaS exit transactions. It proves your product creates expanding value from existing customers.
Four metrics matter more than the Rule of 40: net revenue retention, customer concentration, growth trajectory, and gross margin structure. Nail these and the composite score takes care of itself.
A Deal Where Rule of 40 Was Meaningless
Two companies. Nearly identical revenue. One scored 52, the other 31. Guess which got the better deal.
We recently advised a B2B SaaS company doing $3.2M ARR. Their Rule of 40 score was 52 — objectively strong. Growth was 28%, EBITDA margin was 24%. On paper, a textbook healthy SaaS business.
The first three buyer conversations told a different story. NRR was 94%. The company was adding new logos fast but losing revenue from existing accounts through downgrades and churn. One customer represented 22% of ARR. And growth had decelerated from 45% two years prior.
The company scoring 52 on the Rule of 40 received 4.5x ARR offers. The company scoring just 31 received multiple offers above 7x ARR. The “worse” score got the better deal.
Initial offers came in at 4.5x ARR — well below what the founder expected for a “Rule of 40+” company. The score masked the problems buyers could see underneath.
Contrast that with another engagement: a vertical SaaS company at $2.8M ARR scoring just 31 on the Rule of 40. Growth was 22%, margin was 9%. But NRR was 118%, no customer exceeded 5% of revenue, and growth was accelerating from 15% the prior year. That company received multiple offers above 7x ARR.
Same ballpark revenue. One scored 52 on the Rule of 40, the other scored 31. The “worse” company got the better deal. This isn’t unusual — it’s the norm.
A high Rule of 40 score can mask weak retention, customer concentration, and decelerating growth. Buyers see through the composite number in diligence. What matters is what’s underneath.
What’s Replacing the Rule of 40
The investment community has already moved on. Here’s where they landed.
The investment community is already moving past the Rule of 40. Bessemer Venture Partners introduced the “Rule of X” in 2024, which weights growth more heavily than profitability in the calculation. Their research shows revenue growth correlates with valuation multiples at roughly 2-3x the rate that profit margins do.
For founders in the lower middle market, we use a simpler framework when advising clients on exit readiness:
| Factor | What It Proves | Target |
|---|---|---|
| NRR above 110% | Product creates expanding value | > 110% |
| No customer above 15% of ARR | Reduces concentration risk | < 15% |
| Growth accelerating or stable | Shows momentum, not decay | YoY stable or rising |
| Gross margins above 70% | Confirms software economics | > 70% |
| Owner dependency minimal | Business runs without you | Delegated ops |
A company that checks all five boxes will command a premium regardless of its Rule of 40 score. A company that misses on three of these but scores 50 on the Rule of 40 will get mediocre offers.
If you want to benchmark your readiness across these dimensions, Livmo’s SaaS Valuation Calculator gives you a data-driven starting point beyond a single composite score.
The 5-factor framework above is what we use to advise clients at Livmo. Check all five boxes and you’ll command a premium — regardless of your Rule of 40 score.
How to Use the Rule of 40 Without Being Misled
The Rule of 40 isn’t useless. But using it wrong is worse than ignoring it.
The Rule of 40 isn’t useless. It’s incomplete. Here’s how to use it properly if you’re planning an exit:
- Use it as a screening tool, not a valuation tool. If you’re well below 40, it signals something structural needs attention. But scoring above 40 doesn’t mean you’ll get a premium.
- Decompose the score. A 45 built on 35% growth and 10% margin is worth more than a 45 built on 5% growth and 40% margin — because buyers pay more per point of growth than per point of margin. SaaS Capital’s data confirms this: growth remains the primary driver of valuation multiples across all ARR brackets.
- Track it over time, not as a snapshot. A rising Rule of 40 score signals improving fundamentals. A declining score — even if still above 40 — signals risk that sophisticated buyers will catch.
- Pair it with NRR. If your Rule of 40 is above 40 but NRR is below 100%, you have a growth quality problem that will surface in diligence.
Frequently Asked Questions
What is a good Rule of 40 score for a SaaS company preparing to sell?
A score above 40% puts you in a favorable position, but it’s not sufficient on its own. In 2025-2026 exits, companies with Rule of 40 scores above 40% but weak net revenue retention (below 100%) still received below-market multiples. The score matters most when paired with strong retention, low customer concentration, and stable or accelerating growth.
Does the Rule of 40 affect SaaS valuation multiples directly?
Companies exceeding the Rule of 40 threshold command approximately 10.7x revenue multiples on average, according to Abacum’s analysis. However, the dispersion is significant. Two companies scoring 50 can receive multiples ranging from 4x to 12x depending on growth quality, retention, and concentration metrics. The Rule of 40 correlates with multiples but does not determine them.
What is the Rule of X and how does it differ from the Rule of 40?
The Rule of X, introduced by Bessemer Venture Partners, weights revenue growth at approximately 2-3x the importance of profit margins when assessing SaaS company health. Unlike the Rule of 40, which treats a point of growth and a point of margin as equal, the Rule of X reflects how public and private markets actually price SaaS businesses — growth drives multiples more than profitability does.
How do buyers evaluate SaaS profitability beyond the Rule of 40?
Sophisticated buyers in the lower middle market evaluate profitability through gross margin structure (targeting 75%+), customer acquisition cost payback period (under 18 months), and EBITDA margin trajectory rather than a single snapshot. They also adjust for owner compensation and one-time expenses to calculate true run-rate profitability, which often differs significantly from reported EBITDA.
Next Steps
The Rule of 40 was a useful shorthand when the SaaS industry was younger and simpler. In 2026, it’s a blunt instrument applied to a nuanced decision. If you’re building toward an exit, stop optimizing for a composite score and start building a business with strong retention, diversified revenue, and accelerating growth.
Ready to see what your SaaS business is actually worth — beyond a single score?