The companion metric to this site’s revenue-based SaaS churn & MRR calculator — this tracks customer *count* churn instead, since the two can diverge significantly.
How it works
Customers lost during the period, divided by customers at the period’s start, gives the customer churn rate as a percentage.
What this does not include
This site’s separate SaaS churn & MRR calculator tracks the revenue impact of churn — a business can have a low customer churn rate but a high revenue churn rate if it happens to lose several large accounts, a divergence that calculator’s own documentation calls out directly.
How to use this calculator
- Enter customers at the period start and customers lost during the period.
A worked example
1,000 customers at the start of the period, 50 lost: churn rate = 50 ÷ 1,000 × 100 = 5%.
What the variables mean
| Variable | Meaning |
|---|---|
| Customers at start | Customer count at the beginning of the period |
| Customers lost | How many churned (canceled or didn’t renew) during the period |
Edge cases worth knowing
A small monthly churn rate compounds into a large annual loss. 5% monthly churn sounds modest, but it means losing roughly 46% of a customer base over a year if left unaddressed — the compounding effect is easy to underestimate at a glance.
Zero starting customers makes churn rate undefined — there’s no base to measure the loss against, so the calculator returns no result.
Frequently asked questions
Why track both customer churn and revenue churn?
Because they can tell very different stories — losing many small customers might show high customer churn but low revenue churn, while losing one large account shows the opposite.
What’s a healthy customer churn rate?
It varies enormously by business type — consumer subscription businesses often tolerate higher churn than B2B SaaS companies with fewer, larger, longer-term accounts.
Does new customer acquisition offset churn in this calculation?
No — this calculator measures only the loss rate against the starting base; net customer growth would require separately tracking new customers added during the same period.
