Churn Rate Calculator Widget
Add a churn calculator that does the period conversion right. Readers enter customers at the start and those lost - or start, end and new customers - for a month, quarter or year and get churn, retention and the compounded monthly and annual equivalents, plus gross revenue churn if they add MRR.
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<iframe src="https://a2z.tools/embed/w/churn-rate-calculator" title="Churn Rate Calculator by A2Z Tools" width="100%" height="540" style="border:0;width:100%" loading="lazy" allow="clipboard-write"></iframe>
A plain iframe. Works everywhere, including site builders that strip scripts. Adjust height if your content needs more room.
<div data-a2z-widget="churn-rate-calculator" data-height="540"></div> <script async src="https://a2z.tools/embed.js"></script>
Adds a small script (what it does) that sizes the widget to fit its content, loads it lazily and keeps it isolated from your page's CSS.
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How it works
Customer churn for a period is the number of customers lost divided by the number at the start of that period; customers who sign up during the period are kept out of the denominator. If you only know the counts at the start and end and the number of new sign-ups, lost customers are start + new - end. Converting between periods compounds, because each month's churn applies to the customers who survived the month before: monthly = 1 - (1 - period churn)^(1 / months) and annual = 1 - (1 - monthly)^12. A 3% monthly rate is therefore 30.62% a year, not 36%, and David Skok's rule of thumb that 2% a month is about 22% a year comes out as 21.53%. Gross revenue churn uses MRR instead of heads: MRR lost to cancellations and downgrades divided by MRR at the start. A lost count larger than the starting base, or an end count above start plus new, is rejected as inconsistent.
Calculation method
- Customer churn = customers lost / customers at the start of the period
- Customers lost (flow mode) = start + new - end
- Retention = 1 - churn
- Monthly equivalent = 1 - (1 - period churn)^(1 / months in period)
- Annual equivalent = 1 - (1 - monthly churn)^12 (never monthly x 12)
- Gross revenue churn = MRR lost / MRR at the start
Worked examples
Monthly churn
Inputs: 500 customers at the start; 15 lost in the month
Result: Churn 3.00%; retention 97.00%; annual equivalent 30.62%
1 - 0.97^12 = 0.3062.
Quarterly data
Inputs: 1,000 at the start of the quarter; 90 lost
Result: Quarterly churn 9.00%; monthly equivalent 3.09%; annual equivalent 31.43%
1 - 0.91^(1/3) = 3.09% a month, compounding back to 1 - 0.91^4 = 31.43% a year.
An illustration of standard churn definitions, not financial advice.
Limitations
- Uses the start-of-period denominator; cohort-based and average-base methods give different numbers.
- Gross revenue churn excludes expansion - see the Net Revenue Retention widget for the net figure.
- Assumes churn is steady across the months when converting between periods.
Where publishers use it
- Customer-success blogs explaining retention benchmarks
- SaaS investor-update templates
- Membership, gym and subscription-box owners tracking cancellations
- Telecom and ISP explainer pages on subscriber churn
- Startup-school lessons on unit economics
Questions
Why not multiply monthly churn by 12?
Because churn applies to a shrinking base. Losing 3% a month leaves 0.97^12 = 69.4% of customers after a year, so annual churn is 30.6%, not 36%. The gap widens as churn rises: 8% a month is 63.2% a year, not 96%.
Should new customers be in the denominator?
In the standard simple method, no - churn is measured against customers present at the start. Some teams use the average of start and end counts, which gives a lower rate when the base is growing; whichever you choose, keep it consistent month to month.
What is the difference between customer churn and revenue churn?
Customer churn counts accounts; gross revenue churn counts MRR lost to cancellations and downgrades. Losing many small accounts can mean high customer churn but low revenue churn - 4% of MRR while losing 10% of logos.
What is a good churn rate?
It depends on the market. Small-business SaaS often sees 3-7% a month; mid-market and enterprise products typically report under 1% a month (below about 10% a year). Consumer subscriptions are usually higher still.
Why do new cohorts churn faster?
Recent sign-ups are still deciding whether the product fits; many subscriptions lose a large share of a cohort in months 1-3 and then flatten. A blended monthly rate mixes young and mature accounts, so a company adding lots of trials can report rising churn while its mature cohorts are stable.
How do I count a customer who cancels and returns in the same month?
Count them as neither lost nor new if they return before the period ends, or as lost and new if your billing treats them as a new subscription. In flow mode, reactivations belong in the new-customer figure.
Sources
- SaaS Metrics 2.0 - A Guide to Measuring and Improving What Matters - David Skok, For Entrepreneurs (Matrix Partners) . States that 2% monthly churn means losing about 22% of revenue a year - the compounding the widget applies. Checked 2026-10-01.
- SaaS Metrics 2.0 - Detailed Definitions - David Skok, For Entrepreneurs (Matrix Partners) . Defines MRR churn as lost MRR from churned customers divided by total MRR. Checked 2026-10-01.
Cite or recommend this tool
If you reference this tool in an article, course or documentation, these formats are ready to copy. They are optional - nothing is added to your site unless you paste it.
A2Z Tools Churn Rate Calculator https://a2z.tools/embed/churn-rate-calculator
<a href="https://a2z.tools/embed/churn-rate-calculator">A2Z Tools Churn Rate Calculator</a>
[A2Z Tools Churn Rate Calculator](https://a2z.tools/embed/churn-rate-calculator)
Churn Rate Calculator by A2Z Tools - https://a2z.tools/embed/churn-rate-calculator
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