How to Calculate Churn Rate: Formula and Worked Example

Churn rate is the percentage of customers or revenue you lose in a period, and most SaaS companies lose 5-7% of customers every month, per a Pacific Crest Securities study. To calculate it, divide the customers lost during the period by the customers you started with, then multiply by 100. Pick one time window, count the losses, and divide.

What is churn rate and why does it matter?

Churn rate measures how fast you lose customers or revenue over a fixed period. It matters because retention, not acquisition, is where the money actually compounds.

The economics are lopsided. The Customer Success Association reports that acquiring a new customer costs 5-7 times more than keeping an existing one. Gartner research has been cited for the finding that a 5% cut in churn can raise profit by 25-95%. HubSpot's 2020 State of Marketing survey found 70% of companies rank customer retention as a key goal.

Small churn numbers hide large damage. A business losing 7% of customers monthly loses roughly 58% of them in a year if nothing replaces them. That is the leak you plug before you spend more on acquisition.

How do I calculate churn rate?

Divide the number of customers lost during a period by the number you had at the start, then multiply by 100. That single formula covers customer churn; swap customer counts for recurring revenue and you get revenue churn.

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Worked example: you start the month with 500 customers and 25 cancel. 25 ÷ 500 = 0.05, so your monthly customer churn rate is 5%. If your monthly recurring revenue (MRR) started at $50,000 and you lost $3,000 to cancellations and downgrades, gross revenue churn is 6%.

Follow these steps to calculate it cleanly:

1. Pick one fixed window — monthly is standard for subscriptions.
2. Count customers (or MRR) at the start of the window.
3. Count how many you lost inside that window.
4. Exclude new customers gained during the window from the denominator.
5. Divide losses by the starting number and multiply by 100.

Always label the window. "5% churn" means nothing until you say monthly or annual. To convert monthly to annual, do not multiply by 12. Use 1 − (1 − monthly churn)^12, which turns a 5% monthly rate into about 46% annual churn.

What is the difference between voluntary and involuntary churn?

Voluntary churn is when a customer chooses to leave; involuntary churn is when a payment fails and the account lapses without a decision. You calculate both with the same formula, but you fix them in completely different ways.

• Voluntary churn: cancellations from weak onboarding, missing value, or a cheaper competitor. Fix with product and lifecycle work.
• Involuntary churn: expired cards, insufficient funds, failed retries. Fix with dunning emails and card-retry logic.

Split them in your data. Involuntary churn is often a large share of total churn and the cheapest to recover, because those customers already wanted to stay.

How we track churn while shipping software every day

We build and ship production software with AI daily, and we treat churn as a build-time metric, not a quarterly report. Every subscription product we run writes a cancellation event and a failed-payment event into the same table, so gross and involuntary churn come from one query instead of a spreadsheet rebuilt after the fact.

The trade-off we hit early on: we only tracked logo churn, and it looked fine at 4%. Revenue churn was 9%, because the accounts leaving were our biggest ones. Counting every customer equally hid that our best-paying users were the unhappy ones. Now we watch net revenue churn first and logo churn second.

What broke: our first dunning flow retried a failed card once and gave up, so involuntary churn masqueraded as real cancellations. Adding a three-attempt retry over ten days, plus a plain "your card failed" email, recovered a meaningful slice with about an hour of build work. Cheap fix, direct payback.

How can I reduce churn rate in my business?

Start by separating voluntary from involuntary churn, because the two need opposite fixes. Then attack the largest, cheapest bucket first — usually failed payments.

Stripe's IPO filing noted that the median subscription business sees roughly 10-15% customer churn per year, so a few points of improvement moves real money. Practical moves that work:

1. Add dunning: retry failed cards and email the customer before the account lapses.
2. Strengthen onboarding so new users reach first value fast.
3. Watch net revenue churn, not just logo counts, to catch big-account risk.
4. Talk to churned customers; five exit interviews beat one dashboard.
5. Offer annual plans that reduce monthly cancel opportunities.

Retention is the growth engine. Cutting 6% monthly churn to 3% roughly doubles the average customer's lifetime, which changes every downstream number from payback period to customer lifetime value.