Churn rate: definition, calculation, and retention strategies
Updated on February 22, 2026
Quick definition
Churn rate (or attrition rate) is the percentage of customers or subscribers who stop using a service over a given period. It is one of the most critical indicators for a SaaS because it directly determines the ability to grow: high churn devours newly acquired customers and prevents building a solid base.
How it works
Formula
Churn rate = (Customers lost during the period / Customers at start of period) × 100
Example: 500 customers on January 1st, 25 lost in January → monthly churn = 5%
Churn rate is calculated by dividing the number of customers lost over a period by the number of customers at the start of that period. For a B2C SaaS, healthy monthly churn is below 2–3%. For a B2B SaaS, monthly churn below 1% (less than 12% annual) is considered acceptable.
There are two types of churn:
- Customer churn: number of subscribers lost
- Revenue churn: amount of MRR lost. It can be negative (Negative Churn) when expansions from existing customers offset cancellations — a sign of a very healthy SaaS
Causes of churn are many: poor product-market fit, insufficient onboarding, lack of engagement (dark users), pricing issues, competition, or a change in the customer's situation.
Cohort analysis is essential for understanding churn: it allows you to compare retention across customers acquired at different periods and identify whether improvement actions have had a real impact.
Why it matters
Churn rate is a fundamental health indicator for a SaaS. With 20% annual churn, a company must acquire 20% new customers simply to maintain its base — without generating any growth.
The lower the churn, the more efficient the growth and the higher the company's valuation. Investors scrutinize churn as one of the first indicators during due diligence, as it directly predicts MRR and CLTV trajectory.
How to improve or use it
- 1Identify causes via exit surveys sent to canceling customers.
- 2Analyze cohorts to identify customer profiles with the best retention rate and align your acquisition toward those profiles.
- 3Improve your onboarding so new customers quickly reach the "aha moment".
- 4Identify early churn signals (drop in usage, no logins, negative support tickets) and intervene proactively.
- 5Set up automated re-engagement campaigns for at-risk customers before they decide to cancel.
With Sublim
Sublim lets you detect early churn signals by tracking active-user behavior: drop in login frequency, abandonment of key features, decline in engagement. These behavioral signals, available in real time without third-party cookies, allow your Customer Success team to intervene before the customer decides to cancel.
Frequently asked questions
What is the difference between churn rate and retention rate?
Churn rate measures the percentage of customers lost over a period. Retention rate measures the percentage of customers retained. The two are complementary: a 95% retention rate corresponds to a 5% churn rate. Retention is often presented positively in investor communications, while churn is analyzed internally to identify problems.
What churn rate is considered acceptable for a B2B SaaS?
For a B2B SaaS, annual churn below 5–7% is considered excellent. Between 7% and 12% it is acceptable but warrants attention. Above 15% annual, churn is concerning and requires urgent corrective action. Benchmarks vary by market segment (SMB vs. enterprise) and price point.
What is Negative Churn?
Negative Churn occurs when revenue generated from existing-customer expansions (upsells, cross-sells) exceeds revenue lost to cancellations. It signals a mature SaaS with strong expansion potential. It means that even without acquiring new customers, total MRR would keep growing.
Related terms
CLTV (Customer Lifetime Value) is the customer lifetime value represen…
MRR (Monthly Recurring Revenue) is the monthly recurring revenue repre…
A cohort is a group of users who share a common characteristic at a pr…
Cohort analysis is an analytical method that groups users sharing a co…