Definition
Churn rate is a metric used to measure customer or revenue loss over a defined period. It is particularly important for subscription and recurring-revenue businesses, where customers can cancel, fail to renew, or reduce their recurring spend.
There are several forms of churn, including customer churn and revenue churn. They measure different things and should not be treated as interchangeable.
The calculation methodology also varies by business model. A company should clearly define the population being measured, the period, and the treatment of new customers, reactivations, downgrades, and other changes.
What is customer churn?
Customer churn measures the proportion of customers who leave during a specified period.
A basic formula is:
Customer Churn Rate = Customers Lost During Period ÷ Customers at Beginning of Period × 100
For example, if a company begins a month with 1,000 customers and 50 customers leave:
50 ÷ 1,000 × 100 = 5%
The company's monthly customer churn rate is therefore 5% under this methodology.
What is revenue churn?
Revenue churn measures the recurring revenue lost during a period rather than the number of customers lost.
A simplified calculation is:
Revenue Churn Rate = Recurring Revenue Lost ÷ Recurring Revenue at Beginning of Period × 100
For example, if a company begins a month with $500,000 in recurring revenue and loses $20,000 through cancellations and downgrades:
$20,000 ÷ $500,000 × 100 = 4%
Revenue churn can therefore differ substantially from customer churn.
Customer churn vs. revenue churn
These metrics answer different questions.
Customer Churn | Revenue Churn | |
|---|---|---|
Measures | Customers lost | Recurring revenue lost |
Denominator | Beginning customers | Beginning recurring revenue |
Useful for | Customer retention | Revenue retention |
Can be affected by customer size | Less directly | Strongly |
For example, losing ten small customers may produce high customer churn but relatively little revenue churn.
Losing one very large customer may produce low customer churn but significant revenue churn.
Gross churn vs. net revenue retention
Gross churn measures losses without giving credit for expansion from existing customers.
Net revenue retention (NRR) considers both losses and expansion from the existing customer base.
For example, an existing customer base could lose $50,000 through cancellations and downgrades but gain $80,000 through upgrades.
The company would have experienced revenue churn while still increasing the value of its existing customer base.
Churn and NRR should therefore be considered together when analysing recurring-revenue businesses.
What causes customer churn?
Customers may leave because of:
Product dissatisfaction
Poor customer experience
Pricing
Lack of product usage
Changing customer needs
Competition
Budget reductions
Business closure
Contract expiration
Product-market misalignment
The causes vary by industry and customer segment.
Understanding why customers churn is often more valuable than knowing the headline churn rate alone.
What causes revenue churn?
Revenue can decline because customers:
Cancel completely
Downgrade their plans
Reduce usage
Remove seats
Reduce purchases
Move to lower-priced products
Revenue churn can therefore occur even when the number of customers remains relatively stable.
Why does churn matter?
Churn affects the ability of a company to retain and grow its customer base.
High churn can:
Reduce recurring revenue
Increase the need for customer acquisition
Increase CAC requirements
Reduce LTV
Make forecasting more difficult
Increase pressure on sales and marketing
Low churn can support more predictable recurring revenue and improve the economics of customer acquisition.
However, a "good" churn rate cannot be defined universally. Appropriate levels vary substantially by industry, customer segment, contract structure, pricing model, and company stage.
Churn and LTV
Churn is an important input into many LTV calculations.
If customers remain with a company for longer, their expected lifetime value can increase, assuming other variables remain constant.
For a subscription business with a stable monthly churn rate, a simplified estimate is:
Average Customer Lifetime ≈ 1 ÷ Monthly Churn Rate
At a 5% monthly churn rate:
1 ÷ 0.05 = 20 months
This is a simplified approximation and does not account for changes in churn, customer cohorts, expansion, reactivation, or other complexities.
Churn and CAC
Churn also affects the relationship between customer acquisition cost and customer value.
If a company spends $500 to acquire a customer but that customer leaves shortly afterward, the company may not recover its acquisition cost.
A company with higher retention can potentially recover CAC over a longer customer relationship.
This is why churn is often analysed alongside:
CAC
LTV
Gross margin
Retention
Payback period
Logo churn
"Logo" is often used in business metrics to refer to a customer account.
Logo churn therefore refers to the percentage of customer accounts lost during a period.
It is essentially a form of customer churn terminology commonly used in B2B businesses.
A company should define whether a "customer" represents an individual user, account, organisation, subscription, or another unit.
Churn in B2B vs. B2C
Churn dynamics can differ substantially between business models.
B2C
Consumer subscriptions may have:
Larger customer populations
Shorter contracts
More frequent cancellations
More automated purchasing decisions
B2B
Business customers may have:
Larger contract values
Longer contracts
Renewal cycles
Multiple users per account
More complex purchasing processes
Consequently, churn rates should be compared primarily with relevant peer businesses, rather than using a universal benchmark.
Example
A SaaS company begins January with 500 customers.
During January:
20 customers cancel
10 customers downgrade but remain customers
30 new customers join
Using a simple customer-churn calculation:
20 ÷ 500 × 100 = 4%
The customer churn rate is 4%.
The 10 downgrades do not count as customer churn because those customers have not left. They may, however, contribute to revenue contraction.
Common misconception
A low customer churn rate always means the company has strong retention.
Not necessarily.
A company can have low customer churn while losing a substantial amount of revenue if its largest customers are leaving or reducing their spending.
Conversely, a company can have relatively high customer churn while maintaining strong revenue retention if smaller customers leave while larger customers expand.
For recurring-revenue businesses, customer churn and revenue churn should therefore be analysed separately.
