Compound Monthly Growth Rate Calculator

About this calculator

The compound monthly growth rate (CMGR) is the monthly equivalent of CAGR: the smoothed, constant monthly rate that, if applied every month, would take a starting value to an ending value over a given number of months, accounting for compounding rather than simply averaging the monthly changes. It is calculated as (ending value ÷ starting value) raised to the power of (1 ÷ number of months), minus one.

CMGR is especially common in startup and SaaS reporting, where month-to-month revenue or user growth is often too noisy to interpret directly — a single strong or weak month can distort a simple average — so founders and investors use CMGR to express growth as one clean, comparable figure across pitch decks and board reports. This calculator takes a start value, end value, and number of months to compute the smoothed monthly growth rate.