Rule of 40
Definition
The Rule of 40 is a SaaS performance benchmark stating that a company's revenue growth rate plus its profit margin should equal or exceed 40 %. It balances the tradeoff between growth and profitability, recognizing that high-growth companies can sacrifice margins while profitable companies can accept slower growth.
Formula
Overview
The Rule of 40 provides a single number to evaluate whether a SaaS company is performing at a healthy level when considering both growth and profitability together. A company growing at 60 % with a -20 % profit margin scores 40, as does a company growing at 20 % with a 20 % profit margin. Both are considered healthy under this framework.
The metric is typically calculated using year-over-year revenue growth rate plus EBITDA margin or free cash flow margin. Companies above 40 tend to command premium valuations, while those below may face pressure from investors to either accelerate growth or improve profitability.
The Rule of 40 is most relevant for SaaS companies past the early growth phase, typically $10M+ ARR. At the seed and early stages, high growth rates easily exceed 40 on their own, making the metric less differentiating. As companies mature and growth naturally decelerates, maintaining a Rule of 40 score requires building operational leverage and improving margins.
Example
A SaaS company growing at 35 % YoY with a 10 % EBITDA margin has a Rule of 40 score of 45, above the benchmark, indicating strong combined performance.
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