What it means
Churn matters because acquiring a customer costs money up front while the profit arrives over time. If customers leave before they have repaid what it cost to win them, more marketing spend simply produces more losses, which is why investors in subscription businesses look at churn before they look at growth.
There are two families of churn and they answer different questions. Customer churn counts departing accounts regardless of size, while revenue churn measures the value that left, and the two diverge sharply when a business loses many small customers but keeps its large ones, or the reverse.
Net revenue churn is the version most software businesses report, because it offsets losses against upgrades and expansion from customers who stayed. When existing customers spend more than the ones who leave took away, net revenue churn is negative, which means the base grows even with no new customers at all.
The denominator is where most reporting arguments start. Customers who joined and left inside the same period, seasonal accounts and annual contracts that only come up for renewal once a year can all be counted several defensible ways, so the definition needs writing down and holding steady.
Churn also converts directly into customer lifetime. The reciprocal of the periodic churn rate estimates how many periods an average customer stays, so 4% monthly churn implies a 25 month average life, and multiplying that by monthly revenue gives the lifetime value that has to exceed acquisition cost for the model to work.
In practice
Real-world examples.
Example
A meal kit service reports 9% monthly customer churn but only 6% revenue churn, because the accounts leaving are mostly small single person boxes. Management stops discounting the entry tier and redirects the budget to the family plans, which retain far better.
Example
A business software vendor reports net revenue churn of -2% for the quarter. Around 5% of recurring revenue was lost to cancellations, but seat expansion within surviving accounts added 7%, so the revenue base grew without a single new logo.
Example
A gym chain measures churn monthly and finds it spikes to 14% in the fourth month of membership. It introduces a structured check in at week ten with a trainer, and the month four figure settles back to 8% over the following two quarters.
Formula
Calculation
Customer churn rate = (Customers lost during the period / Customers at the start of the period) x 100
Solstice Software begins May with 2,400 subscribers, each paying $250 a month, and loses 96 of them during the month.
Churn rate = (96 / 2,400) x 100 = 4% per month.
Revenue lost = 96 x $250 = $24,000, against a starting monthly recurring revenue of 2,400 x $250 = $600,000, so revenue churn is also 4%.
Annual retention = 0.96 raised to the power of 12 = 61.3%, meaning annual churn is 38.7% if the monthly rate persists.
Average customer lifetime = 1 / 0.04 = 25 months, so lifetime revenue per customer = $250 x 25 = $6,250. At a gross margin of 80%, lifetime gross profit is $6,250 x 0.80 = $5,000, which comfortably exceeds Solstice's acquisition cost of $1,900 per customer.Case study
Seen in the real world.
Fern Hollow Analytics is a fictional data reporting company used here as an illustrative example, not a real business. It grew from 400 to 1,900 customers in two years and celebrated every month, because the new customer chart pointed steadily upward and nobody was tracking the other side of the equation.
When a prospective investor asked for cohort retention, the finance lead calculated monthly customer churn at 7.5%, implying an average customer life of about 13 months. With an average price of $180 a month, lifetime revenue was roughly $2,340 per customer against an acquisition cost of $2,100, so almost every sale was close to break even before support costs were even counted.
In this illustrative case the response was to stop chasing headline growth for two quarters and rebuild onboarding, add a customer success contact for accounts above $300 a month, and price a longer annual plan. Churn fell to 4.2% monthly, average customer life more than doubled, and the same marketing spend suddenly produced a business worth funding.
Watch out
Common mistakes.
- Quoting a churn rate without saying whether it is monthly or annual. A 5% figure is excellent monthly for some markets and alarming annually for others, so the period must always be attached.
- Comparing customer churn with revenue churn as if they measure the same thing. They routinely differ by several percentage points, and quoting whichever looks better is how boards get misled.
- Multiplying monthly churn by twelve to get an annual figure. Churn compounds on a shrinking base, so 4% monthly gives 38.7% annually, not 48%.
Questions
People also ask.
What is a good churn rate?
It depends heavily on the market, but small business subscriptions often run 3% to 7% monthly while enterprise contracts are frequently under 1%.
Can churn ever be negative?
Customer churn cannot, since you cannot lose fewer than zero customers, but net revenue churn can be negative when expansion from existing customers exceeds the revenue lost.
Does churn include customers who downgrade?
Not in customer churn, because the account is still active, but a downgrade does show up in revenue churn as a reduction in recurring value.
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