What this calculator does
A single month-over-month figure only describes one step. CMGR answers a different question: over several months of ups and downs, what single steady monthly rate, compounded every month, would have produced the same overall result?
It is the monthly equivalent of CAGR, and it is the standard way early-stage and fast-growing businesses report growth, since a young company’s year-over-year figures are often not meaningful yet: there may not even be a full year of history to compare against.
The formula
CMGR is found the same way CAGR is, just with months as the compounding period instead of years: take the ratio of ending to starting value, raise it to the power of one divided by the number of months, then subtract 1. That single monthly rate, compounded for the same number of months, exactly reproduces the actual total growth observed: it smooths away whatever happened in any individual month in between.
| Term | Meaning |
|---|---|
| Starting value | The figure at the beginning of the period. |
| Ending value | The figure at the end of the period. |
| Months | How many months separate the two figures. |
| CMGR | (Ending ÷ starting)^(1/months) − 1: the steady monthly rate that links them. |
The inputs explained
| Field | What to enter |
|---|---|
| Starting value | The figure at the start of the period. |
| Ending value | The figure at the end of the period. |
| Number of months | The number of months between the two figures. |
When to use it
Reporting growth for a business too young for annual figures
A startup six months old has no meaningful YoY number yet. CMGR gives a single, standard growth figure that still means something at that stage, and is directly comparable to other early-stage companies’ reported CMGR.
Smoothing a volatile few months into one number
If growth was strong in some months and flat in others, CMGR gives the single steady rate that would have produced the same net result, without needing to explain every individual month’s story.
Projecting forward from a track record
Once a CMGR is established from historical data, the same rate can be used to project a future value by compounding forward from the most recent figure, though the further out the projection, the less reliable the assumption that the rate holds.
Comparing growth across companies at different ages
CMGR puts a two-month-old product and a two-year-old product on the same footing: both are reduced to “what steady monthly rate got you from your start to your end.”
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
How the CMGR changes as the same total growth spreads over more months
The same starting and ending values, spread across a longer or shorter number of months.
| Months | CMGR | Total growth over the period | Implied annual growth |
|---|---|---|---|
| 3 | 23.3% | 87.5% | 1,136.0% |
| 6 | 11.0% | 87.5% | 251.6% |
| 9 | 7.23% | 87.5% | 131.2% |
| 12 | 5.38% | 87.5% | 87.5% |
| 18 | 3.55% | 87.5% | 52.1% |
| 24 | 2.65% | 87.5% | 36.9% |
How CMGR changes with the size of the outcome, months fixed at 6
A fixed six-month window and starting value, with the ending value varying.
| Ending value | CMGR | Total growth over the period | Value after another 6 months |
|---|---|---|---|
| 8,500 | 1.02% | 6.25% | 9,031.25 |
| 10,000 | 3.79% | 25.0% | 12,500.00 |
| 12,000 | 6.99% | 50.0% | 18,000.00 |
| 15,000 | 11.0% | 87.5% | 28,125.00 |
| 20,000 | 16.5% | 150.0% | 50,000.00 |
| 30,000 | 24.6% | 275.0% | 112,500.00 |
Questions
How is CMGR different from a simple average of the monthly growth rates?
A simple average ignores compounding and can overstate or understate the true rate. CMGR is a geometric measure that, when compounded month by month, exactly reproduces the actual observed total growth: a plain average of monthly percentages generally does not.
What does “implied annual growth” mean here?
It takes the CMGR and compounds it for a full 12 months, showing what that same steady monthly rate would produce over a year. It is only equal to the actual total growth over the period when the period itself is exactly 12 months.
Can CMGR be used to project future values?
Yes, by compounding the ending value forward at the same rate, which is what the “value after another N months” figure shows. The further into the future the projection runs, the less realistic it is to assume the same rate continues unchanged.
Why might CMGR fall as more history is included?
Growth in absolute terms often gets harder to sustain as a business gets larger: an early period of very fast, low-base growth pulls the average up, while a longer track record that includes a maturing phase pulls it back down.
Is CMGR the same thing as MRR growth rate?
CMGR is the general version of that idea. Monthly recurring revenue growth rate, commonly quoted by subscription businesses, is exactly a CMGR calculation applied specifically to MRR figures.
For the single-step version of this comparison, see the month-over-month growth calculator. For the annual equivalent over a multi-year period, use the CAGR calculator.