How to Calculate Churn Rate (3 Methods, Step by Step)

Knowing how to calculate churn rate is table stakes for any SaaS operator, but there’s more than one way to do it — and the method you pick changes the number you report. In this guide we’ll walk through three methods step by step: simple customer churn, revenue churn, and the average-base method that smooths out fast-growing months. Each comes with a worked example using real numbers.

By the end you’ll know exactly how to calculate churn rate for your own business, which method fits your situation, and the pitfalls that quietly corrupt the number if you’re not careful.

Before you start: define the period and the base

Two decisions shape every churn calculation. First, the time period— monthly is standard for early-stage SaaS, annual for enterprise. Second, the base— the set of customers or revenue you’re measuring losses against. Get these two consistent and your churn number becomes trustworthy and comparable over time.

A universal rule: only count customers who existed at the start of the period. New customers who sign up mid-period don’t belong in the denominator, because you’re measuring how well you retained the people you already had.

Method 1: Simple customer churn rate

This is the most common way to calculate churn rate and the easiest to explain to a board.

Customer churn rate = Customers lost ÷ Customers at start of period × 100

Step by step:

• Count your customers on the first day of the period. Say 900.
• Count how many of those cancelled by the last day. Say 45.
• Divide: 45 ÷ 900 = 0.05.
• Multiply by 100: your monthly customer churn rate is 5%.

Simple and clean. Its weakness is that it ignores account value — losing a $9 customer counts the same as losing a $900 one. That’s why you also need the second method.

Method 2: Revenue churn rate

Revenue churn measures lost dollars instead of lost logos, which matters far more for financial planning.

Revenue churn rate = MRR lost during period ÷ MRR at start of period × 100

Step by step:

• Record your MRR at the start of the period. Say $60,000.
• Add up the MRR from customers who cancelled or downgraded. Say $2,400.
• Divide: 2,400 ÷ 60,000 = 0.04.
• Multiply by 100: your revenue churn rate is 4%.

A crucial distinction: this is gross revenue churn, which counts only losses. If you subtract expansion revenue from upgrades, you get net revenue churn, which can go negative. Learn the difference in our guides to revenue churn and net revenue retention.

Method 3: The average-base method

If your customer count changes a lot within the period — common when you’re growing fast — using the starting base alone can distort the number. The average-base method uses the midpoint of your start and end counts.

Churn rate = Customers lost ÷ ((Start + End) ÷ 2) × 100

Step by step:suppose you start with 1,000 customers, add 300, and lose 50, ending at 1,250. The average base is (1,000 + 1,250) ÷ 2 = 1,125. Churn is 50 ÷ 1,125 × 100 = 4.4%. Using the starting base of 1,000 would have given 5%. Neither is "wrong" — but you must pick one and use it every period.

For high-growth companies, the average-base method produces a fairer read. For stable ones, the simple starting-base method is fine and easier to explain.

Putting it together: a full worked month

Let’s run one period end to end so the pieces connect. Suppose you start March with 1,000 customers and $80,000 MRR. During the month:

• 35 customers cancel, taking $2,000 of MRR with them.
• 10 more lapse from failed payments, worth $600 of MRR.
• Existing customers upgrade, adding $2,500 of expansion MRR.
• You sign 120 brand-new customers (excluded from churn math).

Your customer churn rate is (35 + 10) ÷ 1,000 × 100 = 4.5%, of which 1% is involuntary. Gross revenue churn is (2,000 + 600) ÷ 80,000 × 100 = 3.25%. Net revenue churn subtracts the $2,500 of expansion: (2,600 − 2,500) ÷ 80,000 × 100 = 0.125%. Same month, three very different numbers — each answering a different question about the health of your base.

Common mistakes when calculating churn rate

• Mixing new signups into the denominator. This artificially lowers churn and hides real losses.
• Switching methods between periods. Comparing a starting-base month to an average-base month makes your trend meaningless. Consistency beats precision.
• Ignoring involuntary churn.Failed payments and expired cards can be 20–40% of losses and are recoverable — measure them separately.
• Confusing monthly and annual. A 5% monthly churn is about 46% annually, not 60%, because it compounds on a shrinking base.

Converting monthly churn to an annual figure

Once you’ve calculated monthly churn, you’ll often want an annual number for forecasting or board reporting. The instinct is to multiply by 12 — and that’s wrong, because churn compounds on a base that shrinks each month.

The correct conversion is:

Annual churn = 1 − (1 − monthly churn) raised to the power of 12

Take 5% monthly churn. The naive multiplication gives 60%, but the real figure is 1 − (0.95)^12 = about 46%. The gap widens at higher churn rates. Getting this right keeps your annual forecasts honest — overstating churn here can make a perfectly healthy business look like it’s falling apart on a 12-month view.

Which method should you use?

Track customer churn andrevenue churn — they answer different questions. Use the simple starting-base method if your customer count is fairly stable, and the average-base method if you’re growing fast. Whatever you choose, document it and apply it identically every period. See every variation laid out in our churn rate formula reference, and the plain-English churn rate meaning if you want the concept before the math.

Choosing your period: monthly, quarterly, or annual

The period you calculate over should match how your customers buy and how fast your business moves. Each choice has trade-offs:

• Monthlyis the default for early-stage SaaS with month-to-month billing. It catches problems fast, but it’s noisy at low volume, where a couple of cancellations swing the rate.
• Quarterlysmooths that noise and suits businesses with longer sales cycles. It’s a good middle ground once you have a few hundred customers.
• Annual is standard for enterprise SaaS built on annual contracts, where the real churn decision only happens at renewal. Reporting monthly churn on annual contracts overstates stability.

Whatever you choose, keep it fixed. Comparing a monthly churn figure to a quarterly one tells you nothing, so align the period to your billing and stick with it every time you report.

Automating the calculation

Doing this by hand every month is tedious and error-prone once you have real volume — proration, mid-cycle changes, and mixed billing intervals all complicate the count. StripeReport connects to Stripe with a read-only key and calculates customer and revenue churn automatically, using consistent definitions, then delivers the numbers to email or Slack daily. You get a churn rate you can trust without maintaining a fragile spreadsheet, plus ongoing Stripe churn rate tracking.

Key takeaways

• Calculate churn rate by dividing losses by a base — but the base and period you pick change the number.
• Simple customer churn counts logos; revenue churn counts dollars; the average-base method smooths fast growth.
• Only count customers who existed at the start of the period — never mix new signups into the denominator.
• Consistency matters most: pick one method, document it, and apply it the same way every single period.