SaaS Calculators

SaaS Churn Rate & Net Revenue Retention Calculator

Calculate customer churn, gross and net MRR churn, gross revenue retention (GRR) and net revenue retention (NRR) for a month, with their annual equivalents.

One month of data

Convert a churn rate

Churn and retention

Customer churn (month)
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Gross MRR churn (month)
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Net MRR churn (month)
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GRR (month)
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NRR (month)
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MRR from these customers at end of month
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Customer churn, annualised
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NRR, annualised (compounded)
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Formulas

customer churn = customers lost ÷ customers at start gross MRR churn = (churned MRR + contraction MRR) ÷ MRR at start net MRR churn = (churned + contraction − expansion MRR) ÷ MRR at start GRR = 1 − gross MRR churn NRR = 1 − net MRR churn annual equivalent of a monthly rate m: 1 − (1 − m)^12 monthly equivalent of an annual rate a: 1 − (1 − a)^(1/12) annualised NRR = (monthly NRR)^12

The churn definitions follow Andreessen Horowitz, “16 Startup Metrics”, metric #11: “Monthly unit churn = lost customers/prior month total”, “Gross churn: MRR lost in a given month/MRR at the beginning of the month” and “Net churn: (MRR lost minus MRR from upsells) in a given month/MRR at the beginning of the month”. The article warns that net revenue churn “understates the losses (as it blends upsells with absolute churn)”, which is why both are shown. David Skok, “SaaS Metrics 2.0 – A Guide to Measuring and Improving what Matters” (For Entrepreneurs) explains why the two can differ a lot: losing many small accounts barely moves revenue churn, and expansion can make net churn negative.

New customers acquired during the month are left out on purpose: retention measures what happens to the revenue you already had.

FAQ

What is negative churn?

Net MRR churn below zero, i.e. NRR above 100%: expansion from existing customers is larger than what you lose to cancellations and downgrades. Revenue from a cohort then grows even without new customers.

Why is annual churn not 12 × monthly churn?

Each month’s churn applies to the customers who are left, so it compounds: 3% per month is about 30.6% per year, not 36%.

Should I count customers who joined during the month?

Not in this calculation. Customers at start and their MRR are the base; new customers and new MRR belong to growth, not retention.

What is a good churn rate?

It depends strongly on customer size, price point and contract length, so this site does not quote a single benchmark. Track your own trend by cohort and by plan instead.

GRR or NRR, which one matters?

Both. GRR (capped at 100%) shows how much revenue you keep before any upsell; NRR shows whether existing customers grow. A high NRR can hide a leaky base if a few accounts expand a lot.

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