Churn rate is the percentage of customers or recurring revenue that a subscription business loses during a defined period, usually a month or a year. Among SaaS metrics, it is the most direct measure of whether customers keep finding value, because every lost subscription must be replaced by new sales before the business can grow.
Churn appears in two main forms. Customer churn, also called logo churn, counts accounts that cancel; revenue churn measures the monthly recurring revenue lost through cancellations and downgrades. The two can tell very different stories when small customers leave while large ones stay, so mature SaaS teams always report both views side by side.
How churn rate is calculated
The basic formula divides losses during a period by the starting base. Customer churn rate equals customers lost during the period divided by customers at the start of the period. Customers acquired during the period are excluded from the denominator, which keeps new sales from hiding losses.
Revenue churn uses the same logic with monthly recurring revenue (MRR). Gross revenue churn adds MRR lost to cancellations and to downgrades, called contraction, and divides by starting MRR. Net revenue churn also subtracts expansion MRR from upgrades and added seats, so it can become negative when existing customers grow faster than others leave.
The table summarizes the main churn formulas.
| Metric | Formula | What it shows |
|---|---|---|
| Customer churn rate | Customers lost divided by customers at start | Share of accounts that cancel |
| Gross revenue churn | Churned plus contraction MRR divided by starting MRR | Revenue lost from the existing base |
| Net revenue churn | Churned plus contraction minus expansion MRR, divided by starting MRR | Net change from existing customers |
| Gross revenue retention | 100 percent minus gross revenue churn | Revenue kept before expansion |
| Net revenue retention | 100 percent minus net revenue churn | Revenue kept including expansion |
Monthly and annual churn rate
Monthly and annual churn are not related by simple multiplication. Because each month’s losses come from a smaller remaining base, annual churn equals one minus the monthly retention rate raised to the twelfth power. A 2 percent monthly churn therefore corresponds to about 21.5 percent annual churn, not 24 percent.
| Monthly churn | Annual churn | Implied average lifetime |
|---|---|---|
| 1 percent | About 11.4 percent | About 100 months |
| 2 percent | About 21.5 percent | About 50 months |
| 3 percent | About 30.6 percent | About 33 months |
| 5 percent | About 46.0 percent | About 20 months |
| 8 percent | About 63.2 percent | About 12.5 months |
The implied average lifetime, roughly one divided by the monthly churn rate, feeds directly into customer lifetime value. Small churn differences therefore have large effects on how much a company can afford to spend on acquisition.
Churn rate compared with related SaaS metrics
Churn rate is one of several retention and growth metrics that describe the health of recurring revenue. Each answers a slightly different question, and none is sufficient on its own.
| Metric | Question it answers | Relationship to churn |
|---|---|---|
| Logo churn | How many accounts leave | Customer-count version of churn |
| Gross revenue retention | How much revenue stays before expansion | Inverse of gross revenue churn |
| NRR | Does the existing base grow | Includes expansion against churn |
| LTV to CAC ratio | Is acquisition profitable | Lifetime depends on churn |
| SaaS quick ratio | Is growth efficient | Churn and contraction in the denominator |
High net revenue retention can mask weak customer churn. A company that loses many small accounts but expands strongly in a few large ones may report healthy NRR while its product fails for a whole segment.
What drives churn in subscription businesses
Churn has voluntary and involuntary causes. Voluntary churn happens when customers decide to leave; involuntary churn happens when payments fail and subscriptions lapse without an active decision, which in self-serve products can be a substantial part of total churn.
- Weak onboarding and activation leave customers who never reach the product’s core value.
- Poor product fit appears when marketing attracts customers the product was not built for.
- Customer business changes, such as closure, budget cuts or acquisition, cause churn the vendor cannot fully prevent.
- Failed card payments cause involuntary churn that retry logic and payment reminders can recover.
- Price increases and competitor offers trigger cancellations, especially at renewal dates.
Churn levels differ strongly by segment. Products for small businesses and consumers usually churn much faster than enterprise SaaS with annual contracts, so benchmarks only make sense within a comparable segment and contract type.
Measurement mistakes and how to avoid them
Churn figures are easy to distort. Inconsistent definitions of when a customer counts as lost, or mixing monthly and annual plans in one rate, can make the metric look better or worse than reality.
| Error | Effect | Correct approach |
|---|---|---|
| New customers in the denominator | Understates churn during fast growth | Use the starting base only |
| Annual plans counted monthly | Churn appears only at renewal | Report cohorts by contract type |
| Paused accounts ignored | Hidden future churn | Track pauses separately |
| Only customer churn reported | Revenue impact unclear | Report customer and revenue churn |
| No cohort view | Old and new customers mixed | Analyze churn by sign-up cohort |
Cohort analysis is the most reliable view, because it shows how retention develops for customers who joined in the same month and reveals whether product or onboarding changes are actually working.
Understanding it simply
Churn rate shows how many customers stop paying over a month or a year. If a streaming service starts the month with 100 subscribers and 3 cancel, its monthly churn rate is 3 percent.
Think of a bucket with a small hole in it. New customers are water poured in, and churn is the water leaking out. A business cannot grow if the leak is as big as the pour. That is why companies watch churn so closely.
Applied in practice
A SaaS company selling scheduling software to small clinics starts a quarter with 800 customers and 64,000 in MRR. Over three months, 60 customers cancel, which is about 7.5 percent quarterly customer churn, or roughly 2.6 percent per month.
The revenue view looks better: the clinics that left were mostly on the smallest plan, while larger clinics added seats. Gross revenue churn is about 5 percent for the quarter, and expansion brings net revenue churn close to zero.
A cohort analysis then shows that most cancellations come from clinics that never connected their calendar during the first two weeks. The company adds a guided setup call for new accounts, and churn in the next cohorts falls noticeably, which confirms that activation, not pricing, was the main cause.