Month-Over-Month Calculator
Enter last month and this month values to get your month-over-month (MoM) growth rate as a percentage plus absolute change. Switch to CMGR mode to find the average monthly growth rate across any number of months, or use the reverse-solve panel to find what value you need next month to hit a target growth rate.
Formula
Worked example
Revenue was $85,000 in March and $102,000 in April. MoM = (102,000 - 85,000) / 85,000 x 100 = 20%. If that rate held for 12 months the annualized growth would be (1.20)^12 - 1 = 792%. For CMGR over 12 months from $50,000 to $102,000: CMGR = (102,000 / 50,000)^(1/12) - 1 = 6.13% per month.
What is month-over-month growth?
Month-over-month (MoM) growth measures how a metric changes from one month to the next, expressed as a percentage. It is the shortest-interval growth metric most teams track and is calculated as: (current month value minus previous month value) divided by previous month value, then multiplied by 100. Positive numbers mean growth; negative numbers mean decline. MoM is widely used for revenue, active users, subscriber count, leads, and any time-series KPI where monthly momentum matters. Because it reflects just 30 days of activity, it is sensitive to seasonal swings and one-time events, so analysts usually complement it with a 3-month average or CMGR.
MoM vs. CMGR vs. year-over-year
MoM captures the raw, unsmoothed pulse of a business, while the compound monthly growth rate (CMGR) smooths volatility across a longer window, for example six or twelve months, giving investors and boards a cleaner trend line. The CMGR formula is: (ending value / starting value) raised to the power of (1 / number of months) minus 1. Year-over-year (YoY) growth eliminates seasonality entirely by comparing the same month in two different years. Each metric answers a different question: MoM answers "how did we do this month?", CMGR answers "what is our durable growth trajectory?", and YoY answers "how have we changed over the full business cycle?". Early-stage startups tend to report CMGR to investors; mature businesses lean on YoY.
Reverse-solving for a target
The reverse-solve mode answers "what do we need next month to hit a target MoM rate?" The formula rearranges to: target value = current value x (1 + target rate / 100). For example, if revenue this month is $102,000 and you want 15% growth next month, you need $102,000 x 1.15 = $117,300. This is especially useful for setting sales quotas, growth targets, or content volume goals, because it converts a percentage aspiration into a concrete number that can be tracked week by week.
Common mistakes when reading MoM numbers
A single month of exceptional growth can be misleading if it follows an abnormally weak month (the base effect). Seasonal businesses often show strong MoM growth in the run-up to a peak season and sharp declines immediately after, neither of which reflects the underlying business health. Missing or late data skews the baseline. Revenue recognized on different dates month to month can shift MoM even when bookings are stable. To avoid these pitfalls, smooth with a 3-month rolling average, flag one-time events in your commentary, and always report MoM alongside the absolute value so readers can judge materiality.
MoM growth benchmarks by business stage
| Stage | Typical MoM range | Annual equivalent | Context |
|---|---|---|---|
| Pre-seed / Idea | 20-30%+ | 792-1,355%+ | Very small base; high variance |
| Seed / Early traction | 10-20% | 214-792% | Y Combinator benchmark is ~10% |
| Series A | 5-15% | 80-435% | Product-market fit proven |
| Series B+ | 3-8% | 43-151% | Scaling efficiently |
| Growth stage | 2-5% | 27-80% | Predictable, compounding gains |
| Public / Mature | 0.5-2% | 6-27% | Large base; law of large numbers |
Typical month-over-month growth rate ranges observed across company growth stages.
Frequently asked questions
What is a good month-over-month growth rate?
It depends on the stage of the business. Y Combinator has noted that 10% MoM growth is outstanding for an early-stage startup. Seed-stage companies typically target 10-20% per month; Series A companies aim for 5-15%; growth-stage companies often run at 2-5% on a much larger base. For mature public companies, even 1-2% per month compounds to impressive annual numbers. Context matters: 5% MoM on $100 is trivial; 5% MoM on $10 million is $500k in new monthly revenue.
What is CMGR and why is it better than simple average MoM?
CMGR stands for compound monthly growth rate. Instead of averaging 12 individual MoM percentages (which can be distorted by outlier months), CMGR uses the start and end values and the number of months to calculate the single steady rate that would produce the same result. The formula is (end / start) ^ (1 / months) - 1. CMGR is preferred in investor reporting because it captures compounding and eliminates the noise of volatile individual months.
How do I annualize a monthly growth rate?
Raise (1 + monthly rate) to the 12th power, then subtract 1. For example, 5% per month annualizes to (1.05)^12 - 1 = 79.6% per year. A 10% monthly rate annualizes to (1.10)^12 - 1 = 213.8%, which illustrates how compounding amplifies seemingly modest monthly gains over a full year.
Can MoM growth be negative?
Yes, and it is often called month-over-month decline or contraction. A negative MoM rate simply means the metric fell compared to the prior month. For example, if revenue drops from $100,000 to $90,000, MoM growth is -10%. Negative MoM is normal for seasonal businesses in off-peak months; sustained negative MoM is a signal worth investigating for structural issues like churn, pricing problems, or market saturation.
What if my previous month value is zero?
The standard MoM formula breaks down when the previous value is zero because division by zero is undefined. In this case, growth is considered infinite (or simply not calculable with the ratio method). Instead, report the absolute increase and use CMGR only when you have a meaningful starting base.
How is MoM different from month-on-month?
Month-over-month and month-on-month are the same thing, just regional naming conventions. Both abbreviate to MoM and use the identical formula. US usage favors "month-over-month"; UK and Commonwealth usage often says "month-on-month".