What is the SaaS rule of 40?

The Rule of 40 is a quick yet effective way to evaluate the overall health and potential growth of a company. It is widely used in the world of B2B SaaS and is calculated using two key metrics: growth rate and profit margin. The goal is a result greater than 40, which indicates a healthy and sustainable business.

To calculate the SaaS Rule of 40, you simply add the company’s annual growth rate to its profit margin, both expressed as a percentage. Any result under 40 signals potential cashflow problems and requires evaluating business strategy to promote growth while improving profit margins.

Examples

Company A has a growth rate of 25% and a profit margin of 20%, scoring 45 (healthy). However, a 20% slowdown in growth would place them in the danger zone.

Company B has a growth rate of 30% and a profit margin of 5%, scoring an unhealthy 35. They need either a 17% growth bump or a 100% improvement in profit margins to reach health.

How is it Useful During an Economic Downturn?

During economic downturns, when overall market growth slows, the Rule of 40 becomes most valuable. It clarifies what changes companies can make to reach health by combining two often-isolated metrics into one balanced evaluation.

Companies that maintain a score of 40 during turbulent times focus on customer retention, which keeps growth trending positively while carefully managing expenses to improve profit margins. Strategies include offering flexible pricing and payment plans, eliminating non-essential expenses, and continuing product innovation to remain competitive.