Churn and Retention Rate Calculator
Calculate the churn rate and the retention rate from the customers you had at the start and the customers who left during the period, and convert between monthly and yearly rates.
Definitions
- Churn rate = customers lost during the period (out of those at the start) ÷ customers at the start
- Retention rate = 1 − churn rate (the share of customers at the start who were still there at the end of the period)
- The denominator is the customers at the start. Customers acquired during the period are in neither the numerator nor the denominator. A customer who joins and leaves within the same period is not counted in this churn rate. Returning customers are not considered either.
- This is a customer-count churn rate. Revenue churn (for example, the share of monthly revenue lost to cancellations) is not covered.
- There are several conventions for the churn rate (whether the denominator is the customers at the start or an average over the period, and whether it counts customers or revenue). When you compare with someone else's figure, make sure the definitions match.
Converting between periods (compounded)
Retention multiplies across periods: retention over n periods = (retention in one period) to the power n.
- To convert a churn rate c over k months into a rate over m months: 1 − (1 − c)^(m ÷ k)
- Example: with a 5% monthly churn rate, the 1-year (12-month) retention is 0.95¹² = 54.04%, so the churn rate over a year is 45.96% (not 60%, which is 5% × 12).
The conversion assumes the same churn rate every month (or period). Real churn changes from period to period and with how long a customer has been subscribed, so this is only a theoretical guide.
You can choose 1, 3, 6 or 12 months. Converting to a longer period (monthly to yearly) is exact, using fractions. Converting to a shorter period (yearly to monthly) needs a root, so it is calculated with floating-point numbers and shown as a "rounded value".
Edge cases
- 0 customers at the start → the churn rate cannot be calculated (you cannot divide by 0).
- 0 customers lost → churn rate 0%, retention rate 100%. The converted values are 0% too.
- Customers lost = customers at the start → churn rate 100%, retention rate 0%. The converted values are 100% too.
- More customers lost than at the start → an error (enter how many of the customers at the start were lost).
- When you enter the churn rate (%) directly, it is a number from 0 to 100 with up to 6 decimal places.
- The display adds decimal places when needed, so that a value does not look like 0% or 100% only because of rounding.
Examples
- 1,000 customers at the start, 50 lost in 1 month → churn rate 5.00%, retention 95.00%; converted to 3 months 14.26%, to 6 months 26.49%, and to a year 45.96%
- A 3-month churn rate of 14.2625% → monthly 5.00% (1 − (1 − 0.142625)^(1 ÷ 3))
- A 12-month (yearly) churn rate of 30% → monthly about 2.93%
- A 6-month churn rate of 20% → monthly about 3.65%, yearly 36.00%
Notes
- For percentages in general, use the Percentage Calculator. For the change between two values, use the Percentage Change Calculator. To find the original value from a change, use the Reverse Percentage Calculator.
- To turn a churn rate into a customer lifetime value, use the Customer Lifetime Value (LTV) Calculator.
Frequently asked questions
If the monthly churn rate is 5%, is the yearly churn rate 60%?
No. If 5% of the remaining customers leave every month, the retention after a year is 0.95 to the power 12, about 54.04%, and the churn rate is about 45.96%. Multiplying by 12 gives 60%, which counts the customers who already left again and is too high.
Does the churn rate change when I add new customers?
Not with this definition. The churn rate uses only the customers who were there at the start.
How are the churn rate and the retention rate related?
They add up to 100% (retention rate = 1 − churn rate).