Rule of 40
Also called: rule of forty, growth plus margin
The Rule of 40 says a software company's growth rate plus its profit margin should exceed 40 — you can grow fast and lose money, or grow slowly and be profitable, but not fail at both. It became the dominant SaaS benchmark because it captures the trade-off in one number. Its weakness is that which margin you use (EBITDA, free cash flow, operating) changes the answer substantially.
Formula
Revenue growth % + Profit margin % ≥ 40