Use this churn rate calculator to find the percentage of users you lost last month and estimate the monthly revenue associated with those losses. Customer churn rate, also called customer attrition rate, helps subscription businesses track how well they retain their customer base.
How to use the churn rate calculator
Enter the following values for the same month and customer population:
- Total users: Enter the number of users at the beginning of the month, before that month’s losses. Do not use the month-end total or add users acquired during the month.
- Lost users last month: Enter how many users from that starting group left during the month. For a subscription business, this could mean subscriptions that ended, rather than cancellation requests for subscriptions that remain active.
- Avg. monthly revenue: Enter the average monthly revenue per user, not your total monthly revenue. This input is used to estimate lost revenue; it does not affect the churn percentage.
The calculator returns Churn Rate as a percentage and Lost Revenue in dollars per month.
Count the same unit throughout. For example, if you measure paying customer accounts, use accounts for both total users and lost users, and monthly revenue per account. Mixing accounts, individual users, and paid seats will produce misleading results.
The starting user count must be greater than zero. For a consistently defined starting group, lost users should be between zero and the starting total.
Churn rate formula
The calculator divides lost users by the starting user count, then converts the result to a percentage:
Churn rate (%) = (Lost users ÷ Total users at the start of the month) × 100
Using the calculator’s input variables, this is (l ÷ u) × 100, where l is lost users and u is total users at the start.
How lost revenue is calculated
Lost revenue ($ per month) = Lost users × Average monthly revenue per user
In the calculator, this is l × r, where r is average monthly revenue per user.
This output estimates the monthly revenue associated with the users who left. It is not lost profit, a lifetime revenue estimate, or necessarily the revenue missing from that month’s financial statements. Cancellation dates, billing cycles, refunds, and prepaid subscriptions can affect when the loss appears.
Worked example: 5,000 users and 15 cancellations
Suppose you started the month with 5,000 users, lost 15 of them, and earned an average of $10 per user per month.
| Metric | Calculation | Result |
|---|---|---|
| Monthly churn rate | (15 ÷ 5,000) × 100 | 0.3% |
| Estimated lost monthly revenue | 15 × $10 | $150 per month |
A 0.3% monthly churn rate means you lost 3 users for every 1,000 users in the starting group. The corresponding retention rate for that group is 99.7%, calculated as 100% − 0.3%.
How to interpret your churn rate
A lower customer churn rate means a larger share of your starting customer base stayed. However, there is no single “good” churn rate for every business. Contract length, customer type, product maturity, and your definition of a lost customer all affect comparisons.
- Compare matching periods. A monthly churn rate is not directly comparable with an annual churn rate. Track monthly results consistently rather than treating one unusually strong or weak month as a trend.
- Read the percentage alongside the count. Losing one of ten customers produces 10% churn. Losing one of 1,000 produces 0.1%. Small customer bases can show large percentage swings from a single cancellation.
- Separate retention from growth. Low churn helps preserve your customer base, but customer growth also depends on new and reactivated customers. If you lose 15 users and add 10, your total falls by 5; if you add 20, it rises by 5, assuming no other changes.
- Use a consistent loss definition. Decide how to handle failed payments, expired trials, paused accounts, and reactivations before comparing results across months.
Customer churn is not revenue churn
This calculator measures the share of users lost, not the share of recurring revenue lost. Losing several low-priced accounts can have a different financial impact from losing one large account.
The lost-revenue output uses an average. If departing customers pay substantially more or less than that average, it may understate or overstate their actual monthly revenue. When available, add up the recurring revenue of the customers who left for a more precise figure.
The calculator also does not account for upgrades, downgrades, or expansion revenue from retained customers. Those changes matter when evaluating overall recurring revenue performance.
Use the results to improve retention
Start with the reasons behind the cancellations, then choose a specific change to test:
- Review cancellation reasons. Separate product-fit issues, pricing concerns, missing features, and payment failures so that each problem has an appropriate response.
- Compare customer groups. Calculate churn separately by plan, acquisition channel, or signup cohort using consistent definitions. This can reveal problems hidden by the overall average.
- Investigate early departures. If customers leave soon after signing up, review onboarding, setup difficulties, and whether they reach the outcome they expected.
- Measure changes over time. Track both lost-user counts and churn percentages after a retention initiative. Changes in customer mix or seasonality may also influence the result.
For example, reducing losses from 15 to 10 users with the same starting base of 5,000 would lower monthly churn from 0.3% to 0.2%. At $10 per user per month, estimated lost monthly revenue would fall from $150 to $100. That is $50 less monthly revenue lost—not automatically $50 more profit, because retention efforts may have costs.
Related calculators for subscription businesses
- Use the monthly recurring revenue calculator to assess recurring subscription revenue alongside customer losses.
- Explore scenarios with the revenue growth calculator. Lower churn can support growth, but acquisition, pricing, and expansion also affect the outcome.
- Use the customer lifetime value calculator to explore customer value, while checking that its assumptions fit your business.
For broader financial planning, the break-even point calculator, profit calculator, and margin of safety calculator help you examine whether revenue covers costs and how much room you have before reaching break-even. You can find additional tools in the business category.
Build a churn calculator for your business website
A subscription consultant or customer-success agency could offer a calculator that lets prospective clients estimate the revenue associated with customer losses before discussing retention services. Calcopolis lets businesses build customized lead-generation calculators with inputs and explanations suited to their audience, connecting a useful estimate with a relevant next step.