MRR Growth Calculator
Forecast where your MRR lands by combining new business, expansion and churn month over month.
New business won each month.
Upgrades & seat growth, as % of MRR.
Revenue lost to cancellations, as % of MRR.
Projected MRR over 12 months
This free MRR growth calculator projects where your monthly recurring revenue lands over time. Enter your starting MRR plus the new business, expansion and churn you expect each month, and it forecasts your MRR month by month — including the net new MRR you add along the way.
MRR growth is what compounds a SaaS business. Small differences in monthly net new MRR turn into large gaps a year out, so modelling the inputs separately shows you which lever — acquisition, expansion or retention — moves your trajectory most.
How to calculate MRR growth
Each month starts from the previous month's MRR, adds new business and expansion, then subtracts churn. Expansion and churn are applied as a percentage of the current base, so the result compounds: the bigger your MRR, the more a point of churn costs you in absolute dollars.
The number to watch is net new MRR — what you actually add after losses. Keep it positive every month and MRR climbs; let churn outrun new business and it shrinks even while you are signing customers. This is why retention usually beats acquisition for long-run growth.
Net new MRR = new business + expansion − churn. Next month MRR = current MRR + net new MRR.
Start at $20,000 MRR, add $3,000 of new business and 2% expansion ($400) each month, and lose 3% to churn ($600). Net new MRR in month one is $3,000 + $400 − $600 = $2,800, taking you to $22,800 — and the dollar amounts grow as the base does.
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