Financial Glossary
Rule of 40
The Rule of 40 is a SaaS benchmarking metric that holds that a healthy software company's revenue growth rate plus its profit margin (typically EBITDA or free cash flow margin) should sum to 40 or above. A company growing at 60 percent annually can tolerate a 20 percent loss; one growing at 10 percent should be near breakeven or profitable. The rule provides a single number that balances growth and efficiency, widely used by SaaS investors to evaluate stage-appropriate performance and compare companies across different growth profiles.
Problem & Application
Early-stage SaaS founders often focus exclusively on growth rate and ignore margin until a fundraise forces the conversation. A company sitting at 80 percent growth with a 50 percent EBITDA loss scores 30 on the Rule of 40 -- below the benchmark despite impressive top-line momentum. As growth inevitably decelerates, the margin side of the equation must improve or the score deteriorates further. Founders who build unit economics discipline early -- understanding gross margin, customer acquisition cost, and churn in dollar terms, not just percentages -- are better positioned to hit Rule of 40 benchmarks at scale. Investors at Series B and beyond often use Rule of 40 as a screening filter before engaging with a deal.
In Short
The Rule of 40 is a quick but powerful health check for SaaS businesses. Tracking it regularly forces founders to confront the trade-off between growth investment and profitability before investors raise it for them.