Customer retention
Customer churn calculator
Calculate the share of a starting customer cohort that has left by period end. Separate customer loss from revenue loss.
Your inputs
Starts with illustrative data. Calculations happen in this page; input values are not submitted by this calculator.
Count unique paying customers, not subscriptions or free trials.
Exclude customers who joined during the period and customers who returned before period end.
Customer churn
5%
Customer retention
95%
For the measurement period you chose.
The calculation
Customer churn = customers lost from the starting cohort ÷ starting customers × 100
Rounded for display. Read the assumptions below before comparing this result with your billing system.
What this number includes
- Use the same cohort and a completed period for both counts.
- Count unique paying customers. Exclude free plans and trials.
- The lost-customer input is already adjusted: exclude joined-and-churned customers and those who churned and reactivated during the period. Do not subtract those customers again.
- Customer churn weights each account equally. Review revenue churn too, especially when contract values vary.
Definition reference: ChartMogul: customer churn definition. Methodology reviewed September 15, 2026.
A worked example
Illustrative example: losing 10 of the 200 paying customers present at the start gives 5% customer churn and 95% customer retention.
Should new customers enter the denominator?
Not in this starting-cohort calculation. Use the customers present at the beginning, and count losses only from that cohort.
What is a good churn rate?
There is no universal target. Compare equivalent periods, customer segments, price points, and business stages. This tool calculates a rate; it does not assign a benchmark.
Your next question
Which signup cohorts, plans, and acquisition channels are losing customers?
Connect your data in SyneHQ, inspect the query behind your answer, and save a dashboard for your next review.