Measure growth and marketing · Calculator
Compound Monthly Growth Rate Calculator
Calculate CMGR, total percentage growth and absolute change from your starting and ending values.
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Your rate, next to real ones
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These are month-over-month changes in total visits, not CMGR, so compare direction and size rather than decimals.
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Over time
Smoothed growth checkpoints
| Elapsed months | Smoothed value |
|---|---|
| 0 | 1,000 |
| 3 | 1,189.2 |
| 6 | 1,414.2 |
| 9 | 1,681.8 |
| 12 | 2,000 |
What is compound monthly growth rate (CMGR)?
Compound monthly growth rate (CMGR) is the constant monthly rate that would take a number from its starting value to its ending value over the same number of months. A business that doubles in 12 months has a CMGR of about 5.95%, whatever happened in between.
How the calculation works
CMGR = (ending value ÷ starting value)^(1 ÷ elapsed months) − 1. Multiply by 100 to express it as a percentage.
Worked example
Going from 1,000 to 2,000 over 12 months is 100% total growth and about 5.95% compounded monthly growth. January to December contains 11 monthly intervals; January to the next January contains 12.
Assumptions and limitations
CMGR describes a smoothed rate between two observations. It does not show monthly volatility or forecast future growth. A zero starting value has no defined percentage growth. Use the same units and measurement method at both endpoints.
Frequently asked questions
How is CMGR different from average monthly growth?
Averaging monthly percentages overstates growth when months vary. A month of +100% followed by a month of −50% averages +25%, yet ends exactly where it started, which is a CMGR of 0%. CMGR compounds, so it always reproduces the real ending value.
How many months should I enter?
The number of intervals between your two observations, not the number of months listed. January to December is 11 intervals; January to the following January is 12.
Can I use CMGR to forecast?
Only as an explicit assumption. It summarises two endpoints. It says nothing about month-to-month volatility or whether the rate will continue.
Why is there no result when the starting value is zero?
Growth from zero has no defined percentage: any ending value is an infinite increase. Measure from the first month with a positive value instead.
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