Net revenue retention (NRR) calculator
Net revenue retention (NRR) calculator
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How it is calculated
NRR = (starting MRR + expansion − contraction − churned MRR) ÷ starting MRR × 100
GRR = (starting MRR − contraction − churned MRR) ÷ starting MRR × 100
Both formulas look only at the customers you had at the start of the period. New customers won during it are excluded. GRR can never exceed 100%, because it ignores expansion. NRR can.
Worked example
A SaaS had 50,000 MRR from existing customers twelve months ago. Those customers expanded by 8,000, downgraded by 2,000 and churned 4,000.
NRR = (50,000 + 8,000 − 2,000 − 4,000) ÷ 50,000 = 104.0%. GRR = (50,000 − 2,000 − 4,000) ÷ 50,000 = 88.0%. The gap between the two is the expansion carrying a 12% leak.
How to read your result
These bands are Mazo’s working thresholds. The 103% median and 118% top-decile figures are SaaS Capital’s, for bootstrapped B2B SaaS above $3M ARR; a younger company will not match their sample.
| Range | Reading | What it means |
|---|---|---|
| Under 85% | Leaky | Fix retention before spending on acquisition. |
| 85% to 100% | Shrinking base | Growth depends entirely on new customers. |
| 100% to 110% | Growing base | SaaS Capital’s median is about 103%. |
| 110% and over | Strong | SaaS Capital’s top 10% sits near 118%. |
How to improve it
Read GRR before NRR
A healthy NRR can hide a poor GRR. If GRR is 80% and expansion from a few large accounts lifts NRR to 105%, your base is leaking and your result depends on a handful of customers.
Tie price to a value metric that grows
Expansion only happens if what the customer pays grows when their success does: seats, usage, projects. A flat price gives you retention at best.
Find the month customers leave
Churn clusters. If most leave at month 3 or at renewal, the fix sits right before that point: onboarding, a check-in or a clearer renewal.
Put a person on the biggest 10 accounts
Before €1M ARR, a few accounts carry most of the revenue. A monthly call with each costs little and protects the number.
Common mistakes
Including new customers
Anyone who joined during the period must be excluded. Including them turns NRR into total growth and tells you nothing about retention.
Calculating it too early
With 15 customers, one account leaving moves NRR by several points. Read it as a trend, quarterly, on a trailing twelve months.
Treating a monthly figure as an annual one
NRR of 101% in a single month is about 113% a year if sustained. Compare like with like: this tool works for any period, but benchmarks are annual.
FAQ
What is a good net revenue retention rate?
What is the difference between NRR and GRR?
Can NRR be over 100% with high churn?
Do I calculate NRR monthly or annually?
Keep the revenue you win
Mazo finds where your customers drop off and builds the retention plan, then checks in on it every week. €99 a month, 14 days free.
Start 14-day free trial See all free tools →Written by Madalena Rugeroni, founder of Mazo · Updated 10 November 2026. Benchmarks are credited to whoever published them; where a band is Mazo's own it is labelled as a working threshold. Results are a starting point, not financial advice. Mazo is not affiliated with or endorsed by the sources below.