Churn rate calculator
Calculate customer churn and revenue churn for any period, convert monthly churn to annual, check gross and net revenue retention, and see what churn costs you over the next year. Free, no sign-up, nothing leaves your browser.
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The method
How to calculate churn rate
Customers lost in a period, divided by customers you had when it started.
Count only the customers you had on the first day. Customers won during the period are left out of the formula: if they were added to the bottom, a month with strong sales would hide a month of heavy losses. Retention is the other side of the same number: retention = 1 − churn.
Some teams divide by the average number of customers in the period instead, which gives a slightly lower rate when the base is growing. The calculator shows both so you can match the method your reports already use; just keep one method over time.
5% a month
50 ÷ 1,000 = 5%
1,000 customers on day one, 50 cancelled during the month.
95%
1 − 5% = 95%
The 120 new customers do not change either number.
20 months
1 ÷ 5% = 20
Average customer lifetime if churn stays at 5% a month.
Compounding
Monthly churn vs annual churn
5% a month is not 60% a year.
Each month you lose a share of the customers who are still left, not of the original base, so monthly churn compounds. To turn a monthly rate into an annual one, take what stays each month to the power of 12: annual churn = 1 − (1 − monthly churn)¹². The same logic works backwards: monthly churn = 1 − (1 − annual churn)^(1/12).
| Monthly churn | Annual churn | Customers left after a year, of 100 |
|---|---|---|
| 1% | 11.4% | 89 |
| 2% | 21.5% | 78 |
| 3% | 30.6% | 69 |
| 5% | 46.0% | 54 |
| 8% | 63.2% | 37 |
When you enter a quarter or a year, the calculator converts the rate to its monthly equivalent the same way, so rates from different periods can be compared.
Revenue
Revenue churn, GRR and NRR
Losing one big account can hurt more than losing ten small ones.
Revenue churn measures money instead of logos. Gross revenue churn is the recurring revenue lost to cancellations and downgrades, divided by recurring revenue at the start. Gross revenue retention (GRR) is what is left: (starting revenue − cancellations − downgrades) ÷ starting revenue. It can never be above 100%.
Net revenue retention (NRR) also adds upgrades and upsells from the same customers: (starting revenue + expansion − downgrades − cancellations) ÷ starting revenue. Above 100% means existing customers grow faster than they leave, which is often called negative net churn. New customers are not part of either number.
For a reference point, SaaS Capital's 2025 survey of more than 1,000 private B2B SaaS companies found a median annual NRR of 101% and a median annual GRR of 91%. Your own trend over time says more than any benchmark, because retention differs by price point, customer size and contract length.
Money
What churn costs you
Small changes in monthly churn change customer value a lot.
Month after month
The Cost of churn tab follows today's customers without new sales and adds up the revenue that leaves with each lost customer over the horizon you choose.
Margin ÷ churn
Lifetime value = revenue per customer × gross margin ÷ monthly churn. At $80 a month, 75% margin and 5% churn it is $1,200; at 3.5% churn it is about $1,714.
Compare two rates
Enter the churn you think you can reach to see how many more customers stay and how much revenue that keeps. It is an estimate, not a forecast.
Spreadsheets
Churn formulas for Excel and Google Sheets
Customers at the start in B2, customers lost in C2.
Churn rate for the period
Annual churn from monthly churn in D2
Monthly churn from quarterly churn in E2
Net revenue retention
Starting revenue in B5, expansion in C5, downgrades in D5, cancellations in E5. For gross revenue retention, leave out C5.
FAQ
Churn rate questions
How do you calculate churn rate?
Divide the number of customers lost during a period by the number of customers you had at the start of it. 50 lost out of 1,000 is a 5% churn rate for that period.
Should new customers be included?
No. Customers won during the period are not in the starting count, so they are left out. Otherwise strong sales would hide losses.
How do I convert monthly churn to annual churn?
Use annual churn = 1 − (1 − monthly churn)¹². 5% a month is about 46% a year, not 60%, because each month's losses come from a smaller base.
What is the difference between customer churn and revenue churn?
Customer churn counts accounts. Revenue churn counts the recurring revenue they took with them, including downgrades. If large customers leave, revenue churn is higher than customer churn.
What is a good churn rate?
It depends on your market, price and contract length, so the most useful comparison is your own rate over time. For B2B SaaS revenue, SaaS Capital's 2025 survey reported a median annual gross revenue retention of 91%, which is about 0.8% revenue churn a month.
What is negative churn?
Net revenue retention above 100%: upgrades and upsells from existing customers bring in more than cancellations and downgrades take away.
Does the calculator store my data?
No. Everything runs in your browser. The share link keeps your numbers in the address after the # sign, which is not sent to our server.
References
Sources
- Gross and net revenue retention formulas: Stripe, "Gross revenue retention: What it is, how to calculate it, and what it can tell businesses", checked October 8, 2026
- Retention benchmarks: SaaS Capital, "2025 B2B SaaS Retention Benchmarks", September 2025 (median NRR 101%, median GRR 91%; December 2024 compared with December 2023)
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