What Is the Rule of 40?
The Rule of 40 was popularized by venture capitalist Brad Feld as a simple health check for SaaS companies: add your annual revenue growth rate (%) to your profit margin (%). If the sum is 40 or above, the company is considered balanced between growth and profitability — whether it prioritizes one or the other.
Formula: Rule of 40 = Revenue Growth Rate (YoY %) + FCF Margin (%)
A company growing at 60% YoY with −20% FCF margin scores 40. A company growing at 20% with 20% FCF margin also scores 40. Both are considered balanced, despite very different financial profiles. The rule elegantly captures the growth-profitability tradeoff in a single number.
Rule of 40 Benchmarks (2026)
| Score Range | Tier | Example Companies |
|---|---|---|
| 60+ | Elite / Best-in-class | Palantir, Veeva, Datadog (peak) |
| 40–60 | Healthy & capital-efficient | ServiceNow, Cloudflare, HubSpot |
| 20–40 | Adequate — growth or profitability gap | Most mid-stage public SaaS |
| 0–20 | Below benchmark — review GTM/margins | Turnaround situations |
| < 0 | Distressed — urgent attention needed | Companies in revenue decline |
FCF Margin vs. EBITDA Margin: Which to Use?
The Rule of 40 is typically calculated using FCF margin (free cash flow ÷ revenue) by public market investors because FCF is harder to manipulate through accounting choices and reflects actual cash generation. However, some investors and analysts use EBITDA margin or operating income margin, which can yield different results.
FCF margin is the preferred metric for companies with significant stock-based compensation (SBC), because EBITDA adds back SBC while FCF does not — giving a more conservative view of true profitability. On SaaSDB, all Rule of 40 scores use the FCF margin definition: (operating cash flow − capex) / revenue × 100.
Rule of 40 at Different Growth Stages
The Rule of 40 is most meaningful at scale. At $10M ARR, a company can easily hit 100%+ growth — trivially satisfying the rule — while burning significant cash. At $500M ARR, sustaining even 20% growth is difficult, and investors expect the FCF component to carry more weight.
A common heuristic: companies under $100M ARR should focus on growth efficiency (CAC payback, NRR). Companies above $250M ARR should increasingly target Rule of 40+. Companies above $1B ARR that cannot maintain Rule of 40 typically face multiple compression.
How Investors Use the Rule of 40
Public market investors use the Rule of 40 as a quick screen for SaaS quality and as a normalization tool. Two companies growing at 30% might have very different investment cases: one with 30% FCF margin (Rule of 40 = 60) is self-funding growth; one with −30% FCF margin (Rule of 40 = 0) is burning significant cash.
The "Rule of 40-adjusted multiple" — EV/Revenue divided by Rule of 40 score — is increasingly used to compare valuations across companies at different efficiency levels. Companies with higher Rule of 40 scores generally deserve higher revenue multiples.
How to Improve Your Rule of 40 Score
- check_circleImprove gross margin by shifting to higher-margin product lines or reducing COGS
- check_circleAccelerate NRR to generate organic growth without proportional S&M spend
- check_circleReduce sales cycle length to improve payback and incremental FCF
- check_circleAudit S&M spend efficiency — same growth with lower CAC directly improves FCF margin
- check_circleImplement usage-based pricing to grow revenue as customer usage scales