Month over Month Growth Calculator

What is month-over-month growth?

Month-over-month (MoM) growth measures how a metric changed from one month to the next. It’s the standard pulse check for startups and any business tracking fast-moving metrics like MRR, signups, or active users.

The formula: subtract last month’s value from this month’s, divide by last month’s value, multiply by 100. If your MRR was $85,000 in January and $97,000 in February, your MoM growth rate is 14.1%.

MoM growth is noisier than year-over-year growth because it doesn’t filter out seasonal effects. A retail business will almost always look better in November than February. That’s not growth, that’s seasonality. Keep that in mind when reading monthly numbers.

How this calculator works

The quick calculator at the top handles the simple case: two values, one percentage.

The multi-month analyzer does more. Enter 2-24 months of data, and it calculates your Compound Monthly Growth Rate (CMGR), detects growth patterns, generates a narrative summary you can paste into reports, and charts the trend with a 3-month moving average.

CMGR is particularly useful for startups. Investors want to hear “we grew at 12% monthly over the past year” rather than a list of individual monthly figures. The analyzer gives you that number automatically.

The pattern detector classifies your data as accelerating, decelerating, steady, volatile, recovery, or plateau. This helps you describe the trend, not just the numbers.

CMGR vs simple MoM growth

Simple MoM growth shows what happened in one specific month. CMGR smooths it across multiple months into a single compounded rate.

The CMGR formula: (Last Month / First Month) ^ (1 / Number of Months) - 1.

Use simple MoM when you’re diagnosing a specific month’s performance. Use CMGR when you need a single number for a board deck, investor update, or planning model. For a deeper look at the math and Google Sheets formulas, see our month-over-month growth guide.

One thing to watch: CMGR and simple average of MoM rates produce different numbers. A 50% gain followed by a 50% loss doesn’t net to zero. CMGR accounts for this compounding effect.

When to use MoM vs other time periods

Use MoM for metrics that move fast enough to measure monthly. MRR, signups, conversion rates, and churn are common examples.

Use week-over-week growth for product launches, experiments, or any metric where waiting a full month loses signal. Use year-over-year growth for metrics with strong seasonal patterns or when reporting to leadership.

For early-stage startups, MoM is the default. Paul Graham famously recommended tracking weekly growth, but most seed-stage companies report MoM because the data is less noisy.

Common pitfalls

Small base numbers inflate percentages. Going from 100 to 150 users is 50% MoM growth, but it’s 50 people. Always report absolute numbers alongside the percentage.

Seasonal businesses get misleading MoM figures. If your revenue always dips in January, a MoM decline doesn’t mean your business is shrinking. Compare to the same month last year instead.

Don’t confuse compound and linear growth. If you’re adding roughly the same absolute amount each month (linear growth), your MoM percentage will naturally decline as the base grows. That’s not deceleration. It’s math.