What is the formula for churn rate?

Churn rate (customer churn) = Customers lost during the period ÷ Customers at the start of the period × 100. This is sometimes called gross customer churn.

What is retention rate?

Retention rate = 100% − churn rate. If 4% of customers leave, 96% stayed. This calculator reports both for convenience.

Why does net change differ from churn?

Churn measures only the losing side. Net change adds new sign-ups: it is positive if you gained more than you lost, negative otherwise. A business can have high churn and still grow if acquisition is even higher (often a warning sign about long-term sustainability).

Should I count downgrades as churn?

This calculator measures customer (logo) churn — count anyone who left entirely. To measure revenue churn instead, count revenue lost (downgrades plus cancellations) and use revenue figures as the inputs. The math is identical; the meaning shifts.

Is the calculator free?

Yes. It runs entirely in your browser; no signup, no logging, no data leaves the page.

Churn Rate Calculator

Calculate customer churn %, retention %, and net change from start, lost, and gained counts.

Written by Golam Rabbani, Founder & Lead Engineer

This interactive tool requires JavaScript. Read the formula and worked example below; you can compute the result by hand.

How to use this churn rate calculator

Enter the number of customers (or subscribers) at the start of the period.
Enter how many were lost during the period (cancellations, downgrades to zero, hard churn).
Optionally enter how many were gained during the period (new sign-ups).
Press Calculate to see churn %, retention %, net change %, and end-of-period customer count.
Use Copy to share the metrics or paste them into a board report.

About this churn rate calculator

The churn rate calculator turns three numbers — starting customers, customers lost, customers gained — into the headline metrics every subscription business tracks: gross churn (the percentage who left), retention (the percentage who stayed), and net change (growth or shrinkage of the total customer base after accounting for new sign-ups).

Worked example: a SaaS product began the month with 1,000 customers, lost 40 to cancellation, and added 80 new ones. Churn rate = 40 ÷ 1,000 × 100 = 4.00%. Retention = 100 − 4 = 96.00%. End-of-period customers = 1,000 − 40 + 80 = 1,040, a net change of +4.00%. The business is growing despite real churn — exactly the pattern healthy subscription businesses look for.

Revenue churn works the same way with different inputs. If your company started the month with $50,000 MRR, lost $2,500 from cancellations and downgrades, and added $4,000 from new contracts, revenue churn is 2,500 ÷ 50,000 × 100 = 5.00%, net revenue change is +3.00%, and ending MRR is $51,500. Enter those dollar figures directly and the math is identical. For an at-a-glance picture, watch the trend in churn % over time, not a single month. Spikes can be noise, but a steady rise is a real signal worth investigating.

FAQ

What is the formula for churn rate?: Churn rate (customer churn) = Customers lost during the period ÷ Customers at the start of the period × 100. This is sometimes called gross customer churn.
What is retention rate?: Retention rate = 100% − churn rate. If 4% of customers leave, 96% stayed. This calculator reports both for convenience.
Why does net change differ from churn?: Churn measures only the losing side. Net change adds new sign-ups: it is positive if you gained more than you lost, negative otherwise. A business can have high churn and still grow if acquisition is even higher (often a warning sign about long-term sustainability).
Should I count downgrades as churn?: This calculator measures customer (logo) churn — count anyone who left entirely. To measure revenue churn instead, count revenue lost (downgrades plus cancellations) and use revenue figures as the inputs. The math is identical; the meaning shifts.
Is the calculator free?: Yes. It runs entirely in your browser; no signup, no logging, no data leaves the page.