Revenue churn calculator: what share of opening MRR was lost?

Version 1.0.0

Your monthly MRR report may show cancellations and lower payments. This calculator finds what share of the monthly recurring revenue (MRR) you started with is missing at month end. It calls that share gross revenue churn.

Gross revenue churn = (canceled opening MRR + reduced opening MRR) ÷ opening MRR × 100. This follows the broad gross churn formula, with one specific rule for the amounts you enter: use customers who had an active, billable subscription when the month began. Compare each one's MRR at the start and end, and count any missing opening dollars once. This month-end rule is this calculator's choice. A billing report that adds every change during the month may give different totals.

Choose one completed month and one currency. Gains for other starting customers and MRR from new customers do not lower this loss percentage.

Currency Required
Formats results only; it does not convert amounts.
From customers with an active, billable subscription at the start of the month.

Losses from opening MRR

All amounts in USD
Opening MRR for those customers with no active, billable subscription at month end.
Opening minus closing MRR for customers still billable at month end, including a zero-MRR billable subscription.

Count each opening dollar once at month end. Don't use raw event totals. Enter 0 when none.

How to use the revenue churn calculator

  1. For a completed month, list customers who had an active, billable subscription when it began. Add their MRR in one currency. Check what those same customers had at month end. Use monthly amounts, even for plans billed annually.
  2. For each opening customer, count their full starting MRR as canceled if they have no billable subscription at month end. If they still have a billable subscription but their MRR is lower, count only the difference as reduced. Add the two kinds of loss separately. Enter 0 when you have checked and found no loss. A blank amount means missing information, so the calculator cannot produce a result.
  3. Read the loss percentage with the canceled, reduced, and total lost amounts. "Opening MRR still present" is the starting amount less those losses. It leaves out gains and MRR from new customers, so it may differ from your actual closing MRR.

If canceled plus reduced MRR exceeds opening MRR, check whether your report adds up every downgrade or includes customers who joined during the month. The calculator needs each opening dollar counted once at month end.

How lost opening MRR is counted

This calculator compares each opening customer's MRR at the start and end of the month. Their billable state at month end decides how to count a loss:

  • If they have no active, billable subscription, count their full opening MRR as canceled.
  • If they still have a billable subscription, count only the drop below their own opening MRR as reduced. This includes a subscription with $0 MRR if your source still treats it as billable. If their closing MRR is at least their opening MRR, count no loss for them.

If a customer cancels and returns before month end, use their final state. If they cancel one of several subscriptions but remain billable, count any reduction instead of a full cancellation. A customer who starts at $100, drops to $80, recovers to $100, and ends at $80 has lost $20 of opening MRR. Adding both $20 downgrade events would count the same opening dollars twice. If another customer starts at $100, grows to $200, and ends at $50, their loss of opening MRR is $50, even if the billing report shows a $150 downgrade.

A report that sums cancellation and downgrade events can therefore give a different number, sometimes larger than the entire opening MRR. Its event total may be correct for that report. For this calculator, use each opening customer's start and end amounts, or a report that has already counted losses that way.

Reading the result

An April loss of 5%

You began April with $10,000 in MRR. By month end, $400 of that starting MRR was gone because customers had no billable subscription, and $100 was gone because other opening customers paid less. Total lost opening MRR is $500, so gross revenue churn is 5%. The $9,500 shown as "Opening MRR still present" is the starting amount less that loss. A $700 gain for another opening customer changes neither the 5% loss rate nor the $9,500 figure.

"Opening MRR still present" is not your company's ending MRR. It excludes gains above each customer's opening amount and all MRR from customers who joined during the month. With positive opening MRR, 0.00% means no opening MRR was lost, and 100.00% means it was all lost. <0.01% means the actual rate is positive but below 0.01%. If opening MRR is 0, the rate is Unavailable because there is no starting amount to divide by, even if both loss amounts are 0.

Compare months on the same basis

MRR is a monthly recurring run rate, not cash collected or accounting revenue. Use monthly subscription amounts in one currency, without one-time charges or tax. Stripe's MRR guidance explains the distinction. Keep the same billing source and its rules for active subscriptions, discounts, effective dates, and time zones when you compare months. ChartMogul's MRR movement guide shows how one source classifies changes and chooses when to record them. This calculator uses the totals you enter; it cannot inspect or check the customer records behind them.

For the share of accounts lost, use the customer churn calculator. For the opening customer group's result after gains, use the net revenue retention calculator. For the full-company MRR change, including new customers, use the MRR waterfall calculator. Find more in SaaS tools.