This Series A Churn Calculator measures the share of customers or recurring revenue lost during a selected period. It is designed for venture-backed teams that need a consistent churn figure for board reporting, forecasting, and retention planning.
Enter the opening base, the amount lost, and the period length. The calculator reports period churn, monthly-equivalent churn, retained amount, and annualized retention so you can compare results across reporting windows. Use customer counts for logo churn or recurring revenue for revenue churn, but do not mix the two in one calculation.
1. Choose the basis
Select customers for logo churn or recurring revenue for revenue churn.
2. Enter the opening base
Use the active customer count or recurring revenue at the beginning of the period.
3. Enter losses
Include cancellations or revenue lost during the same period.
4. Set the period
Enter the number of months represented by the data.
5. Review the rates
Compare period churn with the monthly-equivalent and annualized retention results.
The opening and lost values must use the same basis and unit. The monthly conversion assumes churn compounds evenly through the period; actual month-to-month churn may vary.
A higher churn rate means more of the opening customer or revenue base was lost during the period.
This is a cohort-style opening-base measure and does not subtract new customers or expansion revenue.
Given
Calculation
Period churn = 35 / 1,000 = 0.035. Monthly-equivalent churn is also 3.50% because the period is one month.
Result
Churn rate = 3.50%; retained customers = 965.
The company kept 96.50% of its opening customer base for the month.
No. Use the active base at the start of the measurement period. New customers acquired during the period do not change opening-base churn.
Logo churn uses customer counts. Revenue churn uses recurring revenue and can show a different pattern when accounts have different contract sizes.
Yes. Enter three months as the period length. The calculator converts the total quarterly churn into a compounded monthly equivalent.
Include downgrades in revenue churn if they reduce recurring revenue. Do not count them as logo churn unless the customer fully leaves.
Compounding a monthly churn rate over 12 months magnifies repeated losses. It is a run-rate view, not a guarantee of actual annual performance.