What is Churn Rate?
Definition
Churn rate (also called customer churn rate or attrition rate) is the percentage of customers who cancel or stop paying for your product during a given time period. It is the inverse of retention — if your monthly churn rate is 5%, your monthly retention rate is 95%. Churn rate is the foundational metric for understanding how well a subscription business retains its customers.
Detailed Explanation
Churn rate is deceptively simple to define but nuanced in practice. The basic formula is: (Customers lost during period / Customers at start of period) x 100. However, the details matter: how do you count customers who downgrade? What about customers who pause? Do you use the start-of-period count or an average? Each approach gives slightly different results.
Most SaaS companies track churn rate monthly and annually. Monthly churn compounds — a seemingly small 3% monthly churn means you're losing 31% of your customers per year (1 - 0.97^12 = 0.31). This compounding effect is why even small improvements in monthly churn have massive annual impact.
Churn rate should always be broken down into voluntary churn (customer chose to leave) and involuntary churn (payment failed and wasn't recovered). These require completely different solutions. Voluntary churn needs product improvements, better customer success, and competitive positioning. Involuntary churn needs better payment recovery: smart retries, dunning sequences, and card updater services. Many companies track only total churn and miss that 20-40% of it is the easily solvable involuntary type.
Why It Matters
Churn rate determines the ceiling of your growth. No matter how good your acquisition engine is, high churn creates a "leaky bucket" that prevents sustainable growth. At 5% monthly churn, you need to acquire 5% new customers every month just to stay flat. The math is unforgiving: a SaaS company acquiring 100 new customers/month with 5% churn plateaus at 2,000 customers. The same company at 2% churn plateaus at 5,000. Reducing churn is often 5-10x more cost-effective than increasing acquisition because retained customers have zero acquisition cost.
How to Calculate
Monthly Churn Rate = (Customers who cancelled during the month / Customers at the start of the month) x 100. Annual Churn Rate = 1 - (1 - Monthly Churn Rate)^12. Example: Start of month: 1,000 customers. Cancelled during month: 30. Monthly churn rate = 30/1,000 = 3%. Annualized = 1 - (1 - 0.03)^12 = 31.2%.
Practical Example
A SaaS startup has 500 customers in January and loses 25 during the month. Monthly churn rate = 25/500 = 5%. Annualized, that's 46% — nearly half their customers will churn in a year. After implementing dunning automation (recovering involuntary churn) and improving onboarding (reducing voluntary churn), they reduce monthly churn to 2.5%. Annualized, that's 26% — still high, but they've saved nearly 150 customers per year.
Industry Benchmarks
| Segment | Benchmark |
|---|---|
| Enterprise SaaS (annual contracts) | 5-7% annual churn |
| Mid-market SaaS | 1-2% monthly / 10-20% annual |
| SMB SaaS | 3-5% monthly / 30-45% annual |
| B2C Subscription | 5-10% monthly / 45-70% annual |
| Best-in-class overall | <5% annual gross churn |
Related Terms
Revenue Churn
Revenue churn (also called MRR churn or dollar churn) is the percentage of recurring revenue lost fr...
Involuntary Churn
Involuntary churn (also called passive churn or delinquent churn) occurs when a customer's subscript...
Voluntary Churn
Voluntary churn occurs when a customer makes a deliberate, conscious decision to cancel their subscr...
NRR (Net Revenue Retention)
Net Revenue Retention (NRR), also called Net Dollar Retention (NDR), measures the percentage of reve...
LTV (Customer Lifetime Value)
Customer Lifetime Value (LTV, CLV, or CLTV) is the total revenue a business can expect from a single...
MRR (Monthly Recurring Revenue)
Monthly Recurring Revenue (MRR) is the total predictable revenue a subscription business earns each ...