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MRR Forecast Calculator

Forecast MRR over time using new MRR plus expansion, contraction, and churn rates.

An MRR forecast helps you sanity-check growth assumptions and understand which lever matters most: new customer acquisition (new MRR) or retention and expansion (NRR).

This calculator models a simple monthly MRR bridge: starting MRR plus new MRR, expansion, minus contraction and churn, repeated for the number of months you choose.

Prefer an explanation- Read the guide.
Related definitions:mrrnet new mrrnew mrrexpansion mrrcontraction mrrchurned mrrnrrgrr
MRR forecasting: a simple bridge model (new, expansion, churn)Revenue retention curves: GRR vs NRR over time (how to model)NRR vs GRR: differences, formulas, and how to use bothRetention & churn hub: cohorts, GRR/NRR, and retention curves
 
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Recurring revenue from brand-new customers (not expansions).
$
 
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%
 
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Tip: you can type commas (e.g., 10,000).

Example

Using the default inputs, the result is:
$244,000.00
Starting MRR
$100,000
New MRR added per month
$12,000
Monthly expansion rate (existing MRR)
2%
Monthly contraction rate (existing MRR)
0.5%
Monthly churn rate (existing MRR)
1.5%
Months to forecast
12

How to calculate

  1. Enter your starting MRR (current recurring run-rate).
  2. Estimate new MRR added per month (from new customers).
  3. Set monthly expansion, contraction, and churn rates for existing MRR.
  4. Choose a horizon (e.g., 6-24 months) and compare scenarios.

Formula

Ending MRR = iterate monthly: MRR_next = MRR + new + (expansion% * MRR) - (contraction% * MRR) - (churn% * MRR)
  • Rates apply to the current month's MRR base (not cohort-based).
  • New MRR is constant each month for simplicity.
  • This is a planning model; use cohort retention curves for higher precision.

FAQ

Is this the same as NRR forecasting-
This model includes both new customer growth (new MRR) and existing customer dynamics (expansion, contraction, churn). NRR focuses only on existing customers; here we show the implied monthly NRR from your assumptions.
What horizon should I use-
For execution planning, 6-12 months is common. For longer-range strategy, use scenarios (base/optimistic/conservative) because small rate changes compound quickly.

Common mistakes

  • Mixing time units (monthly churn with annual inputs).
  • Using expansion/churn rates that imply impossible outcomes (e.g., churn > 100%).
  • Treating this as a replacement for cohort-based retention curves; use cohorts for higher accuracy.

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Quick checks

  • Keep time units consistent (monthly vs annual) across inputs and outputs.
  • Segment by cohort/channel/plan before trusting a blended average.
  • Use the related guide to avoid common definition and denominator mismatches.