What is Customer Churn Rate?
Churn rate is the percentage of customers you had at the start of a period who were gone by the end of it. It's the single most important number in any recurring-revenue business, because it sets a hard ceiling on growth: at 5% monthly churn, you replace your entire customer base every twenty months just to stand still. Note the denominator — customers at the start, not the average or the end — otherwise fast growth will mask the leak.
Why it matters
- It caps the size your business can reach. Steady-state customer count equals new customers per month divided by churn rate, and no acquisition budget escapes that arithmetic.
- It drives lifetime value directly: LTV is roughly average revenue per customer divided by churn rate, so halving churn doubles what every customer is worth.
- Rising churn is the earliest reliable signal of a product, onboarding, or expectation-setting problem — usually months before it shows in revenue.
The formula
Churn Rate = (Customers Lost ÷ Customers at Start of Period) × 100
- Customers Lost
- — customers who cancelled or failed to renew during the period
- Customers at Start of Period
- — active customers on the first day — not an average, and not including new joiners
How to use this calculator
- 01Pick a period that matches your billing cycle — monthly for monthly plans, annual for annual contracts. Mixing them produces meaningless numbers.
- 02Count active customers on day one of the period.
- 03Count how many of those specific customers left before the period ended. Customers who signed up and cancelled inside the same period are a separate problem worth tracking on their own.
- 04Enter both, then repeat the calculation using revenue instead of customer count to see whether you're losing your smallest accounts or your largest.
Worked example
A subscription business started March with 1,200 active customers and lost 36 of them by the end of the month.
- Customers at start = 1,200
- Customers lost = 36
- Churn rate = (36 ÷ 1,200) × 100 = 3.0% per month
- Annualised, roughly 1 − (1 − 0.03)^12 ≈ 30.6% of the base per year
3% monthly churn implies an average customer lifetime of about 33 months. It's healthy for SMB software and would be alarming for an enterprise contract book.
Industry benchmarks
Compiled August 2026
B2B SaaS — enterprise
0.5% – 1% monthly
Annual contracts and switching costs keep it low.
B2B SaaS — SMB
3% – 5% monthly
Smaller customers churn faster and more unpredictably.
B2C subscription apps
5% – 10% monthly
Low commitment, low switching cost.
Subscription boxes / DTC
6% – 12% monthly
Heavily concentrated in the first three cycles.
Common mistakes
- Using average or end-of-period customers as the denominator, which understates churn during periods of growth.
- Reporting only customer churn when revenue churn tells a different story — losing five small accounts and one large one are not equivalent.
- Ignoring involuntary churn from failed payments, which is often a quarter of total churn and is fixable with dunning rather than product work.
- Annualising monthly churn by multiplying by twelve; compounding means 5% monthly is about 46% annually, not 60%.
How to improve your Churn Rate
Fix the first thirty days
Churn concentrates in early tenure. A customer who reaches their first real outcome inside the first month churns at a fraction of the rate of one who never does.
Model what retention is worth →Recover failed payments before you chase win-backs
Involuntary churn is the cheapest churn to fix. Card retries and pre-expiry notices typically recover a meaningful share of it with no product change.
Put a number on the revenue you're losing
Churn as a percentage is easy to tolerate. The same figure expressed as annual revenue lost is what gets it prioritised.
See the revenue impact of churn →Frequently asked questions
What's an acceptable churn rate?+
It depends on who you sell to. Roughly 0.5–1% monthly is expected for enterprise software, 3–5% for SMB software, and 5–10% for consumer subscriptions. The direction of travel matters more than the absolute number.
What's the difference between customer churn and revenue churn?+
Customer churn counts accounts; revenue churn counts dollars. A business can lose 5% of customers and only 1% of revenue if the departures are small accounts — or lose 1% of customers and 8% of revenue if one large account leaves.
What is negative churn?+
Net revenue churn below zero — when expansion revenue from existing customers exceeds the revenue lost to cancellations. It's the strongest position a subscription business can be in, because revenue grows even with zero new customers.
How do I annualise a monthly churn rate?+
Compound it rather than multiplying: annual churn = 1 − (1 − monthly rate)^12. At 5% monthly that's about 46% annually, not 60%.
Related calculators
Put this calculator on your site
Free to embed, no attribution required beyond the link the widget already carries. It posts its height to the parent window as marketing-calculators:height if you want to size the frame exactly.
<iframe src="https://markcelerate.com/embed/churn-rate-calculator" title="Customer Churn Rate Calculator" width="100%" height="520" style="border:1px solid #ddd;border-radius:6px" loading="lazy"></iframe>