# Churn Rate Calculator

URL: https://speedycalculator.com/calculators/finance/churn-rate/
Last updated: 2026-10-25

> The churn rate calculator works out the percentage of customers you lose in a period, the matching retention rate and the average customer lifetime, and converts a monthly churn rate to an annual one.

## Inputs

- Customers at the start of the period
- Customers lost during the period
- Period length

## Results

- Churn rate
- Retention rate
- Average customer lifetime
- Annualised churn

## Formula

```
Churn rate = customers lost ÷ customers at the start × 100
Average customer lifetime = 1 ÷ churn rate (in periods)
Annual churn = 1 − (1 − monthly churn)^12
```

## Explanation

Churn is the opposite of retention. Subscription businesses track it monthly; a 5% monthly churn means losing almost half of customers in a year. Reducing churn is usually cheaper than acquiring new customers.

### How to use the Churn Rate Calculator

- **Customers at the start of the period**
- **Customers lost during the period**
- **Period length**

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 and how many cancelled 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

FieldWhat to enterCustomers at the start of the periodA numberCustomers lost during the periodA numberPeriod lengthChoose one: Month, Quarter, Year

### What each result means

- **Churn rate** = [Customers lost during the period]÷[Customers at the start of the period]×100
- **Retention rate** = 100 - [Churn rate]
- **Average customer lifetime** = [Customers at the start of the period]÷max([Customers lost during the period], 0.000001)
- **Annualised churn** = (1 - (1 - [Churn rate]÷100)^[Period length])×100

### Example values

How the main result changes when **Customers at the start of the period** changes and everything else stays at the example values above:

Customers at the start of the periodChurn rate (%)1,00071,5004.672,0003.52,5002.83,0002.334,0001.75

## Worked example

Inputs — Customers at the start of the period: 2,000; Customers lost during the period: 70; Period length: Month.

Results — **Churn rate = 3.5 %**; Retention rate = 96.5 %; Average customer lifetime = 28.6 periods; Annualised churn = 34.79 %.

## FAQ

**What is a good churn rate?**
For B2B SaaS, under 1–2% a month; consumer subscriptions are often 5–7%.

**How is customer lifetime related to churn?**
Lifetime is roughly 1 ÷ churn: 5% monthly churn means about 20 months.

**Should new customers count?**
No – measure churn on customers present at the start of the period.

**What formula does the Churn Rate Calculator use?**
Churn rate = customers lost ÷ customers at the start × 100.