METHOD & GUIDANCE
How this calculation works
Keep every input on the same time basis—for example, one month or one financial year—and do not mix cash figures with accrual figures. Tool IQ recalculates every output immediately; nothing you enter is saved or sent to us.
How to use the result
Measure customer and revenue churn for the same cohort and period, then compare retention work with the cost of replacing lost customers.
Worked example
Losing 50 of 1,000 opening customers is 5% customer churn and 95% retention before considering 80 newly acquired customers.
Common mistakes
- Including new customers in the opening denominator.
- Mixing monthly losses with an annual starting base.
- Assuming customer churn and revenue churn are identical.
Frequently asked questions
Is the customer churn calculator free?
Yes. It requires no account and stores no calculation inputs.
Can I use the answer for a formal filing?
No. It is a planning estimate, not accounting, tax, legal or investment advice. Confirm material decisions with a qualified professional.
Which period should I use?
Keep every input on the same basis—for example, one month or one financial year. Use current figures first, then save a cautious scenario for comparison.
Continue the decision
- Customer Acquisition Cost Calculator — Compare acquisition cost with estimated customer value.
- Revenue Growth Calculator — Measure growth and project a future revenue scenario.
Popular small-business decision paths
- Build the next cash-flow forecast
- Measure how quickly invoices become cash
- Estimate how long available cash will last
Method reviewed 5 August 2026. Figures are illustrative and calculated locally in your browser. Official sources are linked where a rule or obligation affects how the result should be used. Read the Tool IQ calculation standard for our checking process, limitations and corrections policy.