BYTETOOLS

Churn Rate Calculator

Calculate customer churn, revenue churn, retention rate, net revenue retention and average customer lifetime from your start-of-period figures.

5.00%
Customer churn / month
95.00%
Customer retention / month
10.00%
Gross revenue churn
105.00%
Net revenue retention
90.00%
Gross revenue retention
-5.00%
Net revenue churn
20.0
Average lifetime (months)
45.96%
Annualised customer churn
1,030
Ending customers
$105,000
Ending recurring revenue

Healthy: expansion more than replaces what you lose, so existing accounts grow on their own.

Customer churn is customers lost divided by the customers you had at the start of the period — new customers won during the period are deliberately excluded from the denominator, which is the convention most SaaS reporting uses. Gross revenue churn counts churned plus contraction MRR, and gross revenue retention is its mirror image — it excludes expansion entirely, so it can never exceed 100%. Net revenue retention adds expansion back and often does. Average lifetime is the 1 ÷ churn approximation, which assumes a constant churn rate and overstates lifetime when churn is front-loaded onto new signups. All figures are yours and stay in your browser.

What is the Churn Rate Calculator?

The ByteTools Churn Rate Calculator works out how fast you are losing customers and revenue. Enter the customers you started the period with and the number who left, and it returns the churn rate, the retention rate and the implied average customer lifetime.

  • Customer churn and retention rate from start-of-period figures
  • Gross and net revenue churn, plus GRR and NRR
  • Average customer lifetime derived as 1 ÷ churn
  • Correctly compounded annualised churn rate
  • Plain-language banding for your net revenue retention
  • Fully offline — no customer data leaves your browser

How to use the Churn Rate Calculator

  1. 1

    Choose whether you are measuring a monthly, quarterly or annual period.

  2. 2

    Enter the customers you had at the start of the period and how many left.

  3. 3

    Optionally add new customers won to see the ending customer count.

  4. 4

    Fill in the revenue section with starting MRR, churned, contraction and expansion MRR.

  5. 5

    Read the churn, retention, NRR and average-lifetime figures.

About the Churn Rate Calculator

The ByteTools Churn Rate Calculator works out how fast you are losing customers and revenue. Enter the customers you started the period with and the number who left, and it returns the churn rate, the retention rate and the implied average customer lifetime.

Add your MRR movement — churned, contraction and expansion — and it also gives gross revenue churn, net revenue churn, gross revenue retention and net revenue retention. NRR is the figure investors look at first, because a business above 100% grows from its existing base even with no new logos.

The maths follows the standard definitions rather than a convenient shortcut: new customers are excluded from the churn denominator, and the annualised rate compounds the period rate instead of multiplying it. Everything is calculated in your browser and nothing is uploaded.

Frequently asked questions

How do you calculate churn rate?

Divide the customers lost during the period by the number of customers you had at the start of it, then multiply by 100. Losing 50 of 1,000 customers in a month is a 5% monthly churn rate. Customers you won during the period are deliberately left out of the denominator.

What is a good churn rate?

For SaaS aimed at small businesses, 3% to 5% monthly is common; enterprise products usually run well under 1% a month. There is no universal benchmark, because a consumer app and a five-year enterprise contract are not comparable — compare yourself to your own trend instead.

What is the difference between customer churn and revenue churn?

Customer churn counts logos; revenue churn counts money. Losing ten small accounts and losing one enterprise account can produce the same customer churn but wildly different revenue churn, which is why healthy companies track both.

What is net revenue retention and why can it exceed 100%?

NRR takes your starting MRR, subtracts churn and contraction, then adds expansion from customers who upgraded. Because expansion is added back, NRR can go above 100% — meaning the existing customer base grew on its own. Anything above 120% is considered best-in-class.

How do I convert monthly churn to annual churn?

You compound it rather than multiplying by 12. The correct formula is 1 − (1 − monthly churn)^12, so 5% monthly churn is about 46% a year, not 60%. This calculator does that compounding for you.

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