# Churn rate calculator: monthly vs annual churn, retention and customer forecast

> Churn rate = customers lost during a period ÷ customers at the start of that period. Monthly churn does not convert to annual churn by multiplying by 12: annual churn = 1 − (1 − monthly churn)¹². So 3% monthly churn is about 31% a year, not 36%. Average customer lifetime is roughly 1 ÷ monthly churn — about 33 months at 3%.

- Interactive version: https://infikeytechnologies.com/tools/churn-rate-calculator
- Type: free instant calculator
- Category: SaaS
- Last reviewed: 2026-10-05
- Publisher: Infikey Technologies (https://infikeytechnologies.com)

## Example result (default inputs)

| Input | Value |
| --- | --- |
| Period of your numbers | One month |
| Customers at start of period | 1,000 |
| Customers lost during period | 30 |
| New customers during period | 60 |
| Forecast length | 12 months |

**Churn rate per month: 3%.** Losing 30 of 1,000 customers per month is 3% churn — 3% a month and 30.6% a year.

High churn: you lose 31% of customers a year. Look at onboarding and the first 90 days, where most cancellations start.

| Metric | Value |
| --- | --- |
| Monthly churn (equivalent) | 3% |
| Annual churn (compounded) | 30.6% |
| Retention rate per month | 97% |
| Average customer lifetime | 33.3 months |
| Customers at end of period | 1,030 |
| Today’s customers left after 12 months | 69.4% |
| Customer count where churn equals new customers | 2,000 |

### Forecast customers (same churn and new customers)

| Item | Value | Detail |
| --- | --- | --- |
| Month 1 | 1,030 |  |
| Month 2 | 1,059 |  |
| Month 3 | 1,087 |  |
| Month 4 | 1,115 |  |
| Month 5 | 1,141 |  |
| Month 6 | 1,167 |  |
| Month 7 | 1,192 |  |
| Month 8 | 1,216 |  |
| Month 9 | 1,240 |  |
| Month 10 | 1,263 |  |
| Month 11 | 1,285 |  |
| Month 12 (selected) | 1,306 |  |

- With constant new sign-ups, the customer base levels off where churned customers equal new ones — about 2,000 customers here.

Open this result on the website: https://infikeytechnologies.com/tools/churn-rate-calculator?period=month&start=1000&lost=30&new=60&months=12

## Use from a link or API

Add these query parameters to https://infikeytechnologies.com/tools/churn-rate-calculator (pre-filled page), https://infikeytechnologies.com/tools/churn-rate-calculator.md (this plain-text page) or https://infikeytechnologies.com/api/tools/churn-rate-calculator (JSON).

| Parameter | Meaning | Accepted values |
| --- | --- | --- |
| `period` | Period of your numbers | one of month, quarter, year |
| `start` | Customers at start of period | number from 1 to 1000000000, default 1000 |
| `lost` | Customers lost during period | number from 0 to 1000000000, default 30 |
| `new` | New customers during period | number from 0 to 1000000000, default 60 |
| `months` | Forecast length | number from 3 to 60 (months), default 12 |

- SMB SaaS, monthly: https://infikeytechnologies.com/tools/churn-rate-calculator?period=month&start=1000&lost=35&new=70&months=24
- Enterprise, annual: https://infikeytechnologies.com/tools/churn-rate-calculator?period=year&start=200&lost=14&new=50&months=36
- Consumer app, quarterly: https://infikeytechnologies.com/tools/churn-rate-calculator?period=quarter&start=50000&lost=9000&new=12000&months=12

## How it is calculated

- **Churn rate**: customers lost ÷ customers at start of period
- **Monthly churn from a longer period**: 1 − (1 − period churn)^(1 ÷ months in period)
- **Annual churn**: 1 − (1 − monthly churn)^12
- **Average lifetime**: 1 ÷ monthly churn (months)

## Monthly to annual churn conversion

| Monthly churn | Annual churn (correct) | × 12 (wrong) | Average lifetime |
| --- | --- | --- | --- |
| 0.5% | 5.8% | 6% | 200 months |
| 1% | 11.4% | 12% | 100 months |
| 2% | 21.5% | 24% | 50 months |
| 3% | 30.6% | 36% | 33 months |
| 5% | 46% | 60% | 20 months |
| 7% | 58.1% | 84% | 14 months |
| 10% | 71.8% | 120% | 10 months |

## Customer churn vs revenue churn

This calculator measures customers. Revenue churn measures the recurring revenue lost, including downgrades, and can be very different if large and small customers behave differently.

For revenue retention including upgrades, use the net revenue retention calculator.

## How to reduce churn

- Guide new customers to their first success quickly with onboarding.
- Watch product usage and contact accounts whose activity drops.
- Offer annual plans and pause options instead of cancellation.
- Ask every cancelling customer why, and fix the top reasons.
- Handle failed card payments with retries and reminders — involuntary churn is often a large share.

## FAQ

### How do you calculate churn rate?

Divide the number of customers lost during a period by the number of customers at the start of it. Losing 30 of 1,000 customers in a month is 3% monthly churn.

### How do you convert monthly churn to annual churn?

Annual churn = 1 − (1 − monthly churn)¹². 3% monthly churn is about 30.6% annual churn.

### What is a good churn rate?

It depends on the customer type: products for small businesses often see a few percent monthly churn, while enterprise software aims for well under 1% a month.

### Should new customers be included in the churn calculation?

Not in the denominator. Use customers at the start of the period so that new sign-ups do not hide churn.

### What is the difference between churn and retention?

Retention rate is 1 − churn rate for the same period. 3% monthly churn means 97% monthly retention.

## Get expert help

Send these results to an Infikey Technologies specialist from the form on https://infikeytechnologies.com/tools/churn-rate-calculator#estimate or via https://infikeytechnologies.com/contact.

More free calculators: https://infikeytechnologies.com/tools.md

## Disclaimer

This calculator is provided free for general information and planning only. Results are estimates based on the inputs you enter and the assumptions described on this page, reference data such as published prices may change, and actual costs and outcomes will differ. Nothing on this page is financial, legal, tax, investment or other professional advice. Infikey Technologies Private Limited, Infikey Technologies LLC and their directors, employees and affiliates make no warranty, express or implied, about the accuracy, completeness or suitability of this tool or its results, and accept no liability for any loss or damage, direct or indirect, arising from its use or from reliance on its results. Verify all figures independently and seek professional advice before making any decision. Use of this tool is at your own risk.