Customer retention rate isolates loyalty: new customers are removed so that strong acquisition cannot hide poor retention. Increasing retention by a few percentage points can raise profit sharply because existing customers cost less to serve.
How to use the Customer Retention Rate Calculator
- Customers at the start
- New customers during the period
- Customers at the end
Results update as you type, and every field accepts the units shown in its menu.
How it works
Enter the number of customers at the start of the period, at the end, and the new customers gained during it.
Tips
- Use figures for the same period (a month, a quarter or a year) for every input so ratios compare like with like.
- Track the metric over time – the trend usually tells you more than a single value.
- Compare your result with industry benchmarks, which vary a lot between sectors.
- Treat the result as a starting point for a decision, then check the assumptions behind each input.
Common mistakes to avoid
- Mixing monthly and yearly numbers in the same calculation.
- Using revenue where the formula needs profit (or the other way round).
- Forgetting hidden costs such as taxes, fees, overheads or your own time.
Inputs explained
| Field | What to enter |
|---|---|
| Customers at the start | A number |
| New customers during the period | A number |
| Customers at the end | A number |
What each result means
- Customer retention rate = ([Customers at the end] – [New customers during the period])÷[Customers at the start]×100
- Attrition (churn) rate = 100 – [Customer retention rate]
- Customers lost = [Customers at the start] – ([Customers at the end] – [New customers during the period])
Example values
How the main result changes when Customers at the start changes and everything else stays at the example values above:
| Customers at the start | Customer retention rate (%) |
|---|---|
| 250 | 184 |
| 375 | 122.67 |
| 500 | 92 |
| 625 | 73.6 |
| 750 | 61.33 |
| 1,000 | 46 |
Formula
Retention rate = (customers at end − new customers) ÷ customers at start × 100Churn rate = 100% − retention rateWorked example
Inputs — Customers at the start: 500; New customers during the period: 80; Customers at the end: 540.
Results — Customer retention rate = 92 %; Attrition (churn) rate = 8 %; Customers lost = 40.
Frequently asked questions
What is a good customer retention rate?
It varies: around 80% or more is strong in many B2B markets.
Why subtract new customers?
So you measure how many existing customers stayed, not how many you added.
How can I improve retention?
Better onboarding, service, loyalty rewards and listening to feedback.
What formula does the Customer Retention Rate Calculator use?
Retention rate = (customers at end − new customers) ÷ customers at start × 100.