Churn Rate
Also: Customer Churn, Attrition Rate, Revenue Churn, Logo Churn
Churn rate is the percentage of customers or revenue lost over a period. It measures how fast a business loses its existing customer base.
What It Is
Churn rate measures the rate at which customers stop doing business with a company over a defined period (a month, quarter, or year). It is one of the most watched retention metrics in subscription and recurring revenue businesses. Churn can be expressed two ways:
- Customer churn (logo churn): the share of customers who cancel or do not renew.
- Revenue churn: the share of recurring revenue lost, often tracked as gross revenue churn (revenue lost before expansion) and net revenue churn (revenue lost after upgrades and cross-sells from retained customers).
A common formula for customer churn:
`Churn rate = (Customers lost during period / Customers at start of period) x 100`
If a company starts a month with 1,000 customers and loses 40, the monthly churn rate is 4 percent.
Why it matters
Churn directly shapes growth, valuation, and unit economics.
- Growth ceiling: high churn forces you to acquire new customers just to stand still. Growth only happens when new and expansion revenue outpaces churn.
- Lifetime value: churn determines average customer lifetime. At 4 percent monthly churn, the average customer stays about 25 months (1 / 0.04).
- Profitability: acquiring a new customer typically costs far more than retaining one, so reducing churn improves return on acquisition spend.
- Net revenue churn below zero (negative churn) means expansion revenue exceeds losses, a strong signal investors prize.
How it is used in practice
- CFOs use churn to forecast recurring revenue, model lifetime value to acquisition cost (LTV:CAC) ratios, and assess revenue durability for planning and valuation.
- CMOs segment churn by cohort, channel, plan, or persona to find where retention breaks and to target win-back campaigns.
- Data teams build predictive churn models that flag at-risk accounts using usage signals, support tickets, and payment data.
Teams pair churn with retention rate (its complement) and watch trends rather than single numbers.
Concrete Example
A SaaS firm starts the quarter with 200 monthly recurring revenue (MRR) of $500,000. During the quarter it loses $30,000 from cancellations and downgrades but gains $50,000 from upsells to existing customers.
- Gross revenue churn = 30,000 / 500,000 = 6 percent.
- Net revenue churn = (30,000, 50,000) / 500,000 = -4 percent (negative, meaning the existing base grew).
This shows why a single churn number can mislead: the same company has positive gross churn but healthy negative net churn.
Frequently asked questions
How do you calculate churn rate?
Divide the customers lost during a period by the customers you had at the start of that period, then multiply by 100. A company that begins a month with 1,000 customers and loses 40 has a monthly churn rate of 4 percent. The same logic applies to revenue: replace customer counts with recurring revenue amounts.
What is the difference between customer churn and revenue churn?
Customer churn (also called logo churn) counts how many accounts leave; revenue churn measures how much recurring revenue you lose. They diverge when your departing customers are much smaller or much larger than average: losing ten small accounts and one enterprise contract can produce identical logo churn with very different revenue impact.
What does negative net revenue churn mean?
It means the upgrades and cross-sells sold to your retained customers exceed the revenue lost to cancellations and downgrades, so the existing base grows without any new logo. Investors treat negative net churn as a strong signal of revenue durability. It is only possible when a business has real expansion levers such as seats, usage tiers, or additional modules.
How does churn rate affect customer lifetime value?
Churn sets the average customer lifetime, which drives lifetime value. At 4 percent monthly churn, the average customer stays roughly 25 months (1 divided by 0.04), and halving churn roughly doubles that duration. Since acquiring a customer usually costs far more than keeping one, cutting churn improves the LTV:CAC ratio faster than spending more on acquisition.
Why can a single churn number be misleading?
Because gross and net figures can point in opposite directions. Take a company at $500,000 MRR that loses $30,000 to cancellations and downgrades in a quarter while adding $50,000 in upsells: gross revenue churn is 6 percent, net revenue churn is minus 4 percent. Read churn as a trend, broken down by cohort, plan, or channel, and always alongside retention rate.