Churn Rate Calculator

What is customer churn rate?

Customer churn rate shows the percentage of the customer base that existed at the beginning of a selected period and was lost during that same period. It is useful for SaaS companies, subscription services, ecommerce stores, service businesses, and other companies with repeat customers.

This is a customer-count metric, not revenue churn. One large lost account can have little effect on customer churn but a significant effect on lost revenue.

How to calculate customer churn rate

Record active customers immediately before the period begins. Then count how many people or accounts from that exact group stopped being customers during the period. Divide those losses by the starting count and multiply by 100.

Customers at Start and Customers Lost must cover the same period. Do not divide losses from one month by a customer base recorded for a different month, quarter, or year.

Customer churn rate formula

Customers Churned per 100 expresses the same churn rate as an expected count for every 100 starting customers.

Churn rate vs retention rate

Churn describes the lost share of the starting group. Retention describes the share remaining at period end. In this simple model every starting customer is either retained or lost, so churn rate and retention rate add to 100%.

High retention does not guarantee sufficient revenue, gross margin, or customer acquisition performance. Low churn alone also does not prove that a business is profitable or growing.

Which customers should be counted?

Customers Lost must come from the group counted at the start. A business should define a lost customer consistently before comparing periods. For a SaaS company it may be a canceled or nonrenewed subscription; for an account service it may be a closed account.

For a repeat-purchase business, churn may mean no qualifying purchase within a specified inactive window. Whatever rule is selected, apply the same cancellation, nonrenewal, closure, or inactivity rule to every comparison.

Why new customers are excluded from the churn formula

New customers were not present at the start, so they cannot be retained members of the starting group. Adding them to the denominator or subtracting them from losses can hide churn in the original customer base.

Acquisition can grow total customers while churn remains high. Track new customers separately and use this calculation to evaluate what happened to the group that was already active when the period began.

How to choose a measurement period

Choose a window that matches the business model, customer buying cycle, contract length, and reporting cadence. Monthly measurement may fit frequently billed subscriptions, while quarterly or annual periods may better fit longer contracts or infrequent repeat purchases.

Use the same period length and lost-customer definition when comparing results. Measurement Period labels the calculation; it does not change the formula.

Monthly vs quarterly vs annual churn

Monthly, quarterly, and annual churn cover different lengths of exposure and should not be compared directly without that context. Calculate each rate from the customer base at the start of its own period and losses from that same starting group.

This calculator does not convert or annualize churn. Simply multiplying monthly churn by 12 can be inaccurate because customer losses compound and the customer base can change over time.

Customer churn rate calculation example

Suppose a company starts a month with 1,000 customers and loses 50 customers from that starting group:

1. Customers Retained: 1,000 − 50 = 950.
2. Customer Churn Rate: 50 ÷ 1,000 × 100 = 5.00%.
3. Customer Retention Rate: 950 ÷ 1,000 × 100 = 95.00%.
4. Customers Churned per 100: 50 ÷ 1,000 × 100 = 5.
5. Retained-to-Lost Ratio: 950 ÷ 50 = 19:1, or 19 retained customers for every one lost customer.

How to interpret your churn rate

There is no universal good churn rate. A useful comparison depends on the business model, measurement period, contract length, customer segment, product maturity, acquisition channel, gross margin, customer lifetime value, the definition of a lost customer, and source-data quality.

Compare consistent periods and investigate underlying causes. A small customer base may create sharp percentage swings, and an overall average can hide differences between cohorts, pricing plans, and customer segments.

Common churn calculation mistakes

• Mixing customer losses from one period with the starting customer base from another.
• Counting customers who joined during the period as part of the starting group.
• Subtracting new customers from lost customers to report a lower rate.
• Changing the definition of a lost customer between periods.
• Treating customer churn as revenue churn or directly comparing periods of different lengths.
• Multiplying monthly churn by 12 as an annual result.

Limitations of a simple churn calculation

This snapshot does not show why customers left, how churn differs across cohorts, plans, or segments, or how the base changed within the period. A small base can produce volatile percentages, and an average can conceal important customer differences.

It does not calculate revenue churn, MRR churn, ARR churn, retention revenue, forecasts, or customer lifetime value. The result is a reference for analysis and comparison, not a guarantee of future retention.