Canonical formula calculator
CHURN RATE
The percentage of customers you lose in a given period — the quiet killer of subscription businesses.
Worked example
How the number is worked out
A bookkeeping subscription. It started the month with 240 clients and lost 12.
Starting from
Working
Five percent a month means the average client stays about twenty months. Every new client signed replaces one leaving before it adds anything — which is why churn is worth reading before an acquisition budget.
What this tells you
Churn rate is the percentage of your customer base that leaves in a given period. Monthly churn under 1% is healthy for most subscription businesses. Monthly churn above 5% is a crisis. Annual churn over 30% means you are running a customer treadmill, not a growing business.
When to use it
Calculate churn monthly. Watch the trend more than the absolute number. Compare against industry benchmarks if you can find them. Use it to decide whether to invest in customer success or in new acquisition — when churn is high, fixing churn beats spending more on acquisition every time.
What it doesn’t tell you
Churn rate does not tell you why customers leave, which customers leave (your best ones or your worst), or whether churn is concentrated in new customers (onboarding problem) or long-term customers (product problem). The number is the alarm; the diagnosis takes more work.
Reckon it, don’t just calc it
A calculator gives you today’s number. Reckon takes your plan to make your own money and checks it against what’s real — your margin, your price, what it takes to hit the take-home you want. No AI, no guessing — the same input always gives the same answer.