Sub-year CAGR calculator

Monthly CAGR Calculator

Annualize growth measured over a number of months, or start with a known annual CAGR and convert it to the equivalent monthly compound rate.

Monthly-period calculator

Calculate CAGR from a number of months

The annualized CAGR uses months ÷ 12 as the elapsed years. The equivalent monthly compound rate is shown separately.

Annualized CAGR

31.4534%

Monthly compound rate
2.3052%
Total growth
20%
Elapsed years used for CAGR
0.666667

Annualized CAGR → Monthly compound rate

0.9489%

How monthly-period CAGR works

Convert the number of months to years by dividing by 12, then use the standard CAGR formula.

CAGR = (Ending ÷ Starting)^(12 ÷ Months) − 1

Convert annual CAGR to a monthly rate

If I already know the annual CAGR, I take the twelfth root of its annual growth factor. The result is the equivalent constant monthly compound rate.

Monthly Rate = (1 + Annual CAGR)^(1 ÷ 12) − 1

Last verified

2026-09-20

Calculation methodology

Calculation methodology