Churn Rate Calculator
The Leak in the Bucket
Growth is easy to celebrate and easy to overstate if you're not also watching how many customers or how much revenue is leaving at the same time. Churn rate measures that loss directly, either by counting customers who left or by measuring the revenue that left with them — two numbers that don't always move together.
The Formula
Revenue Churn Rate = (Revenue Lost / Revenue at Start of Period) × 100
Retention rate is simply the complement: 100 minus the churn rate.
Why Customer Churn and Revenue Churn Can Diverge
Losing a large number of low-value customers can produce a high customer churn rate but a modest revenue churn rate, while losing a single large account can do the opposite. Tracking both gives a more complete picture than either alone.
| Customers lost | Churn rate | Retention rate |
|---|---|---|
| 20 | 2.0% | 98.0% |
| 50 | 5.0% | 95.0% |
| 100 | 10.0% | 90.0% |
| 150 | 15.0% | 85.0% |
Where This Calculation Matters
- Subscription health checks — churn rate is one of the first metrics reviewed in any recurring-revenue business.
- Cohort analysis — comparing churn rates across customer segments to identify which ones are at risk.
- Retention program ROI — measuring whether an intervention actually moved the churn number.
- Forecasting — churn rate feeds directly into growth projections and lifetime value estimates.
How to Use This Calculator
- Choose Customer Churn Rate or Revenue Churn Rate from the mode selector.
- For Customer Churn Rate, enter Customers at Start of Period and Customers Lost During Period.
- For Revenue Churn Rate, enter Revenue at Start of Period ($) and Revenue Lost During Period ($).
- Select Calculate to see the churn rate and corresponding retention rate.
Related Calculations
Feed this rate into the Lifetime Value Calculator's churn-based mode, or track how new customers are replacing the ones lost with the Customer Acquisition Cost Calculator.