Finance

Rule of 40 Calculator

Find a SaaS company's Rule of 40 score — growth rate plus profit margin.


Rule of 40 Calculator

Advertisement

A widely used SaaS benchmark that exists specifically to stop comparing fast-growing, unprofitable companies against slow-growing, profitable ones on a single metric.

How it works

Revenue growth rate and profit margin (commonly EBITDA or free cash flow margin) are simply added together. A score of 40 or more is the commonly cited passing threshold — reachable by being very fast-growing and unprofitable, slow-growing and highly profitable, or anywhere in between.

What this does not include

The Rule of 40 says nothing about which combination of growth and margin is preferable for a specific company’s stage or investor base — two companies can both score 45 with very different, and not equally attractive, underlying profiles.

How to use this calculator

  1. Enter revenue growth rate and profit margin.

A worked example

A SaaS company growing 30% annually with a 15% profit margin: Rule of 40 score = 30 + 15 = 45 — above the 40 threshold, considered a healthy balance of growth and profitability.

Growth 10%, margin 5%: score = 15 — well below 40, a warning sign for either weak growth or weak profitability (or both).

What the variables mean

Variable Meaning
Growth rate Annual revenue growth rate, as a percentage
Profit margin Profitability margin, as a percentage

Edge cases worth knowing

The Rule of 40 treats growth and profitability as substitutes. A fast-growing but unprofitable company can pass the same way a slower-growing but highly profitable one can — the sum matters, not the individual components.

This is a rough software-industry heuristic, not a universal financial rule — its usefulness is most established for evaluating SaaS and subscription businesses specifically.

Frequently asked questions

Is 40 a hard cutoff?

No — it’s a widely cited rule of thumb, not a formal standard; some investors and analysts use different thresholds or weight growth and margin differently.

Can a company pass with negative margin?

Yes — a company growing 60% with a -15% margin still scores 45, passing purely on growth, which is common for early-stage, high-growth companies prioritizing expansion over profitability.

What margin should I use?

EBITDA margin or free cash flow margin are both common choices — this site’s EBITDA margin and free cash flow calculators can supply that input.

Important: This is general information, not financial advice. Figures are estimates, and your lender or provider decides the real numbers. Check with a qualified adviser before acting on them.

Be the first to rate this

Written by

M. Whitfield

Personal finance writer

M. Whitfield writes the personal finance calculators, covering loans, mortgages, savings, tax and investment maths. The focus is on showing exactly which number goes into a formula and which assumptions a result depends on, so readers can tell when a figure applies to their situation and when it does not. Every finance page states what it does not account for as plainly as what it does.

Reviewed by

A. Whitfield-Reyes

Calculator reviewer — finance

A. Whitfield-Reyes reviews the finance calculators, checking compounding conventions, rate-period alignment, and whether each page is explicit about the costs and tax treatment it leaves out. Financial results are easy to state with false precision, so review focuses on whether the page makes its assumptions visible to a reader who is not looking for them.

How we write and review

Related calculators