Churn rate is the single number that tells you how fast customers are leaving your business. Whether you run a SaaS subscription, a membership program, or a recurring-revenue service, churn quietly compounds: a rate that looks small each month can wipe out most of your customer base over a year. This churn rate calculator takes the customers you started with and the customers you lost, then shows your period churn, your retention, and — most importantly — the annualized churn you would face if that rate kept up all year.
Type in two or three numbers and every figure updates instantly. Switch the measurement period from monthly to quarterly or yearly to see how the same raw counts translate across time horizons.
How to Use
- Enter Customers at Start — the size of your customer base on day one of the period you are measuring. Use paying customers only, not free trials or leads.
- Enter Customers Lost — the number of customers who canceled, non-renewed, or otherwise stopped paying during that same period. Do not include new sign-ups here; this metric counts departures only.
- Choose the Measurement Period — monthly, quarterly, or yearly. The period tells the engine how to annualize your result.
- Read the result card. You will see the period churn rate, the period retention rate, the annualized churn rate (the highlighted figure), the annualized retention rate, and the raw count of customers retained.
The engine uses the standard logo-churn formula and a compounding annualization. A monthly churn of 2.5% does not become 30% annual by simple multiplication — because retention compounds month after month, the true annual churn ends up lower than that naive sum, while still being large enough to demand attention.
The Churn Rate Formula
Logo churn — the most common definition — is simply:
Churn Rate = Customers Lost ÷ Customers at Start
Where:
- Customers Lost is the count of paying customers who left during the period.
- Customers at Start is the paying base on the first day of the period.
If you start a month with 1,000 customers and lose 25, your churn is 25 ÷ 1,000 = 2.5% for that month. Your retention for the same month is 100% − 2.5% = 97.5%.
That monthly figure is useful, but investors, operators, and advisors almost always want the annual number. The correct way to annualize is to compound the monthly retention, not to multiply the monthly churn by twelve:
Annual Retention = (1 − Monthly Churn)¹² Annual Churn = 1 − Annual Retention
Plugging in 2.5% monthly churn: (1 − 0.025)¹² = 0.738, so annual retention is about 73.8% and annual churn is about 26.2%. In other words, holding a 2.5% monthly churn constant means losing roughly a quarter of your base over a year. Compare that to the naive 2.5% × 12 = 30% — compounding helps you a little on the way down, but the result is still severe.
For a quarterly period you raise retention to the 4th power; for a yearly period the exponent is 1 and the period and annual figures are identical.
Why Churn Matters More Than New Sales
In subscription businesses, new-customer growth and churn are two sides of the same ledger. Signing up 100 new customers while losing 120 means your base is shrinking, no matter how strong your sales team is. This is why churn is often called the "leaky bucket": pouring more water in only helps once you slow the leak.
A few rules of thumb used by operators:
- Consumer subscription SaaS often targets monthly churn under 5%.
- Business and enterprise SaaS should aim well under 2% monthly, because longer contracts and stronger onboarding make higher churn look broken.
- A 5% monthly churn implies an average customer lifetime of about 1 ÷ 0.05 = 20 months under a constant-churn model. Cutting monthly churn from 5% to 3% roughly doubles expected lifetime from 20 to about 33 months.
Revenue churn — calculated the same way but on lost recurring revenue instead of lost logos — can move differently from logo churn if you lose small accounts while keeping large ones. This calculator measures logo churn; use a revenue-churn view alongside it if your account sizes vary widely.
Examples
Example 1 — A typical SaaS month. A startup begins March with 1,000 customers and 25 cancel during the month. Churn = 25 ÷ 1,000 = 2.5% monthly. Retention is 97.5%. Annualized with the 12th power, retention is about 73.8% and annual churn is about 26.2% — the headline number to bring to the board.
Example 2 — Zero churn month. A mature product starts a month with 500 customers and loses none. Churn is 0%, retention 100%, and annual churn also 0% — a perfect month, but treat single-month zeros as luck, not trend. Watch rolling 3-month and 12-month averages instead.
Example 3 — A large enterprise base. A platform starts the year with 2,000,000 customers and loses 40,000 in a month. Churn = 40,000 ÷ 2,000,000 = 2.0% monthly. Annualized retention is about 78.5% and annual churn about 21.5% — on a base that large, even a 2-point improvement is worth tens of thousands of retained accounts.
Example 4 — Quarterly measurement. A membership club starts a quarter with 200 members and 10 lapse. Churn = 10 ÷ 200 = 5% per quarter. Raising 0.95 to the 4th power gives annual retention of about 81.5% and annual churn of about 18.5%.
FAQ
What is a good churn rate?
For business SaaS, aim for under 2% monthly churn; consumer subscriptions often run 3–5% monthly. Enterprise products with annual contracts should measure annual churn and target single digits. There is no universal "good" number — compare yourself to your own trailing average and your category benchmark, not to a competitor's marketing deck.
How do I calculate churn rate?
Divide the number of customers who left during a period by the number of customers you had at the start of that period, then multiply by 100. For example, losing 25 customers out of 1,000 gives a churn rate of 2.5%. This calculator does the division and the annualization for you.
Is monthly churn × 12 the same as annual churn?
No. Multiplying monthly churn by 12 overstates annual churn because retention compounds. The correct annual churn is 1 − (1 − monthly churn)¹². For 2.5% monthly churn, the naive estimate is 30% but the compounded annual churn is about 26.2%.
What is the difference between churn and retention?
They are two views of the same event. Retention rate = 100% − churn rate. If churn is 2.5%, retention is 97.5%. Operators watch both: churn shows how fast you lose customers, retention shows how faithfully you keep them.
Should I count new customers in the churn calculation?
No. Logo churn uses only the starting base and the customers who left. Adding new sign-ups to the denominator would understate churn. Some analysts use a starting-plus-average base as a sensitivity view, but the standard and comparable definition is lost divided by starting.
How does churn relate to customer lifetime?
Under a constant monthly churn rate, the average customer lifetime in months is approximately 1 ÷ (monthly churn as a decimal). At 5% monthly churn, lifetime is about 20 months; at 2%, about 50 months. Reducing churn is therefore one of the highest-leverage ways to increase lifetime value.
What is revenue churn versus logo churn?
Logo churn counts customers; revenue churn counts recurring revenue lost divided by recurring revenue at the start. A business can have stable logo churn but rising revenue churn if it loses its largest accounts, or falling revenue churn if it loses mostly small accounts. Track both.
Disclaimer
This churn rate calculator is provided for informational purposes only and does not constitute financial, accounting, or investment advice. Churn figures depend on how you define customers, cancellations, and the measurement window; actual churn varies by business model, contract length, and reporting method. Always confirm your churn and retention definitions against your own analytics and, where relevant, consult a qualified finance or metrics professional before making business decisions.