How many customers are you really losing? Enter two numbers and get churn, retention, the honest compounded annual figure, and average customer lifespan.
Enter both numbers above — your churn and retention rates appear here instantly. Results assume the period is one month (the projections say so where they use it).
Churn rate is the share of customers you had at the start of a period who were gone by the end of it. It is the leak in the bucket every subscription business is trying to fill with new sales, and it matters more than almost any growth number, because churn compounds: lose 5% of customers every month and you do not lose 60% in a year — you lose about 46%, but you must replace nearly half your customer base each year just to stand still. Growth dashboards celebrate new signups; churn is the quieter number that decides whether those signups ever add up to a bigger business.
Churn rate = Customers lost during the period ÷ Customers at the start of the period. Retention is simply 100% minus churn. Two derived figures on this page assume a monthly period: projected annual churn, calculated honestly by compounding — 1 − (1 − monthly churn)12, not by multiplying by twelve — and average customer lifespan, 1 ÷ monthly churn, which at 4% monthly churn is 25 months. That lifespan number is the bridge to lifetime value: a customer who stays 25 months is worth roughly two and a half times one who stays 10, at the same monthly spend.
1. Pick a period — a calendar month is the convention, and the projections on this page assume it.
2. Count customers at the very start of that period. Do not add people who joined during the period to the starting figure; that quietly dilutes the rate.
3. Count how many of those starting customers cancelled, expired or stopped paying during the period, and enter both numbers above.
A service starts the month with 1,000 subscribers and loses 40 of them: churn is 4.0% and retention is 96.0%. Compounded, 4% monthly churn becomes roughly 38.7% over a year — noticeably less than the naive 48% you get by multiplying by twelve, which is why this calculator compounds rather than multiplies. Average lifespan is 1 ÷ 0.04 = 25 months. If the same service cut churn to 2%, lifespan would double to 50 months and annual churn would fall to about 21.5% — which is why a one-point churn reduction is often worth more than a much larger spend on acquisition.
It depends entirely on who the customer is. As rough orientation — not as targets to copy blindly — consumer subscription products often see monthly churn in the mid-single digits or higher, small-business SaaS commonly sits lower, and enterprise contracts churn least of all because switching is slow and contracts are annual. Voluntary churn (customers choosing to leave) and involuntary churn (failed payments) should be tracked separately: involuntary churn is frequently a fifth or more of the total in consumer products, and it is the part recoverable with dunning emails and card-retry logic rather than product changes. Compare your rate against your own history and your segment, and be suspicious of any single benchmark quoted without one.
Wrong denominator: dividing losses by the average or end-of-period customer count instead of the starting count, which understates churn while you are growing. Mixing cohorts: brand-new customers churn at several times the rate of settled ones, so a signup surge can make churn look worse even when nothing about the product changed. Counting pauses as losses (or the reverse) inconsistently between months. Revenue vs customer churn: losing forty small customers and losing four large ones can be the same customer churn with completely different revenue churn — for most businesses the revenue figure is the one that pays the bills, so track both once you can.
Should new customers be included? In the starting count, no. Customers who join and leave inside their first period are usually reported as their own first-month cohort figure; folding them into the main rate hides exactly the onboarding problem you most need to see.
What period should I use? Monthly is standard for subscriptions billed monthly. Annual-contract businesses should measure annually (or per renewal cycle), because monthly figures between renewals are mostly involuntary payment failures.
Can churn be negative? Customer churn cannot, but net revenue churn can: if remaining customers expand their spending by more than departing customers took away, net revenue churn goes below zero — a sign of a very healthy expansion motion.
Are my numbers uploaded? No. Everything is calculated in your browser; nothing you enter leaves your device.