# Retention and churn calculator

> Free retention rate calculator. Get customer retention, churn, customers lost and average lifetime, and convert an annual churn rate to monthly correctly.

Free, no sign-up, runs in the browser: https://analify-ai.scalyax.ai/tools/retention-rate-calculator

See how many customers you keep and lose in a period, how long an average customer stays, and the right way to turn yearly churn into monthly.

## What it calculates

Retention rate is the share of customers you had at the start who are still buying at the end, not counting new ones. Churn is the share you lost. Average lifetime is 1 ÷ churn. Many people divide annual churn by 12 to get a monthly figure; that understates it because churn compounds.

## Formula

```
Lost = Start + New − End
Retention = (End − New) ÷ Start
Churn = Lost ÷ Start
Average lifetime = 1 ÷ churn (in periods)
Monthly churn from annual = 1 − (1 − annual)^(1/12)
```

## Worked example

Inputs:
- Customers at the start: 2000
- Customers at the end: 2100
- New customers in the period: 400
- Annual churn to convert: 50%

Results:
- Retention rate: 85%
- Churn rate: 15%
- Customers lost: 300
- Average lifetime (periods): 6.67
- Monthly churn from annual: 5.6%
- Annual ÷ 12 (understates): 4.2%

## What changes the result

Customers at the end at five values; every other input as in the example.

| Customers at the end | Retention rate | Churn rate |
| --- | --- | --- |
| 1890 | 74.5% | 25.5% |
| 1995 | 79.8% | 20.3% |
| 2100 (example) | 85% | 15% |
| 2205 | 90.3% | 9.8% |
| 2310 | 95.5% | 4.5% |

## How to read the result

Use the same period for all three counts: a month gives monthly churn, a year gives annual churn.
Compare the last two rows to see how much dividing by 12 gets wrong.
For stores without subscriptions, define an active customer clearly, for example a purchase in the last 12 months.

## Questions

**How do I calculate customer retention rate?**
(Customers at the end − new customers) ÷ customers at the start.

**What is the difference between retention and churn?**
They add up to 100%. Retention is the share you kept; churn is the share you lost.

**How do I convert annual churn to monthly?**
Use 1 − (1 − annual churn)^(1/12). Dividing by 12 gives a number that is too low.

**Do you store what I enter?**
No. The calculation runs in your browser and nothing is sent to Analify.

## Use your real numbers

Analify reads customers and their orders from Shopify and shows new and returning customers and repeat purchase rates over time. Analify reads 3 of these 4 inputs live. Try the calculator: https://analify-ai.scalyax.ai/tools/retention-rate-calculator

More free ecommerce calculators: https://analify-ai.scalyax.ai/tools