Rule of 40 SaaS Calculator
Inputs
Results update liveSelect Scenario Preset
Cite this calculator
Results use the inputs you enter and standard formulas documented on this page. Not professional advice.
Last reviewed: August 2026
Rule of 40 Calculator. (August 2026). Useful Tools Online. https://usefultoolsonline.com/rule-of-40-calculator/
Interpretation
How the Rule of 40 Works
The Rule of 40 is a principle created by SaaS investors stating that a software company's growth rate plus its profit margin should exceed 40%. A company growing at 60% with -15% margin scores 45% (healthy hypergrowth), while a 15% growth company needs at least 25% margin.
Watch out
Common mistakes
- Using monthly compound growth without annualizing to YoY (Year-over-Year).
- Mixing EBITDA margin with gross margin rather than Free Cash Flow (FCF) margin.
- Ignoring customer acquisition cost (CAC) payback trends when modeling margin burn.
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FAQ
Frequently asked questions
How the calculation works and where its limits are.
What is the Rule of 40 in SaaS and why do investors track it?
The Rule of 40 is an operational benchmark stating that a healthy software company's combined annual revenue growth rate plus profit margin (typically Free Cash Flow or EBITDA margin) should equal or exceed 40%. It balances hypergrowth with capital efficiency.
Should I use Free Cash Flow margin or EBITDA margin in the Rule of 40?
Free Cash Flow (FCF) margin is preferred by modern tech investors because it captures working capital timing, software capitalized R&D, and actual cash generation. EBITDA margin is also widely accepted.
Can a SaaS company with negative profit margins pass the Rule of 40?
Yes. A hypergrowth startup growing ARR at 70% year-over-year with a -20% operating margin scores 50% (70 - 20 = 50%), passing the Rule of 40 because growth outpaces burn.
Is this Rule of 40 calculator investment or valuation advice?
No. All outputs are standard venture capital benchmarking metrics based on your entered parameters. Consult your board and corporate finance advisors for valuation models.
What should I do if my score falls below 40%?
Audit your unit economics using our Subscription Churn Calculator, evaluate customer acquisition payback periods, and review your gross margins using our Profit Margin Calculator.