How to use this calculator
Calculate business customer retention from start, end, and new customers.
How the calculation works
- Enter the business inputs for the metric.
- The calculator applies the displayed formula.
- Review the result, assumptions, and related tools.
Formula
retention = (end customers - new customers) / start customers x 100
Example
1,100 end customers, 200 new customers, and 1,000 start customers gives 90% retention.
Understanding your result
Use the output as a practical starting point, then review it before using it in an important workflow.
Assumptions and limitations
- Simplified business planning math only.
- This is not accounting, tax, legal, investment, or valuation advice.
Frequently asked questions
Does this require an account?
No. The core tool works without creating a Tool2Do account.
Is my input included in share links or analytics?
No. Tool2Do share actions use the tool page URL and safe metadata, not private values or uploaded files.