Customer Churn Rate Calculator
Test a different scenario
Change any scenario value below. Your original calculation stays unchanged.
Scenario calculations use the same formula and v2.5 validation rules as the main calculator. No scenario values are sent to Borkish.
Calculations and What-If scenarios run in your browser. Borkish does not require you to submit these values to calculate the result.
What the Customer Churn Rate Calculator measures
Churn helps quantify customer loss and retention pressure. Model growth, recurring revenue, acquisition economics and business runway with simple inputs.
The result becomes more useful when every input follows the same definition and reporting period. That keeps comparisons between campaigns, products, customers and time periods meaningful.
When to use this calculator
- Use the Customer Churn Rate Calculator to run simple planning scenarios before making a business decision.
- Compare growth assumptions with current operating performance.
- Identify the variables that have the greatest effect on the result.
Formula
Percentage results are most useful when the numerator and denominator come from the same population and reporting period.
How to use this calculator
- Customers LostUse the value from the same reporting period or scenario as your other inputs.
- Customers at StartUse the value from the same reporting period or scenario as your other inputs.
- Complete the required inputsThe result updates automatically as the values become valid.
- Compare the resultUse a previous period, target or relevant internal benchmark before making a decision.
Worked example
Using the demonstration values — Customers Lost = 50, Customers at Start = 1000 — the calculator returns 5%. The example shows how the formula behaves; replace the demonstration data with your own before using the result for planning.
How to interpret the result
Churn helps quantify customer loss and retention pressure. These calculators support planning and scenario analysis; they are not a substitute for professional financial advice.
Check the definition of Customers Lost, Customers at Start, the attribution or accounting rules behind those inputs, and any important costs or outcomes that the formula does not include.
Common mistakes to avoid
- Using Customers Lost and Customers at Start from different reporting periods or definitions.
- Mixing monthly and annual figures in the same formula.
- Using assumptions that are not updated when the business changes.
Frequently asked questions
What does this calculator do?
Calculate customer churn as a percentage of customers at the beginning of the period.
Where should I get the input values?
Use your own advertising platform, ecommerce system, accounting report, CRM, analytics platform or forecast — whichever source is authoritative for the metric. Keep all inputs on the same basis and date range.
Is there one good result I should target?
Usually not. A useful target depends on your margins, acquisition model, operating costs, channel, market and business goals. Your own historical performance is often a better starting benchmark than a generic number.
Can I use this for forecasting?
Yes. Enter forecast values to model a scenario, but treat the output as an estimate based on those assumptions rather than a prediction of future performance.
What to calculate next
Churn helps quantify customer loss and retention pressure. A single metric rarely explains the whole decision, so compare this result with the related cost, conversion, margin or growth metrics below before acting on it.
Calculate the percentage of starting customers retained through a period.
Calculate customer acquisition cost from sales and marketing spend.
Estimate gross-margin customer lifetime value from order value, purchase frequency, lifespan and gross margin.
Keep reporting periods and metric definitions consistent when moving between calculators. That makes the comparison more useful than treating each result as a standalone benchmark.