Growth calculator

Churn and Retention Calculator

Calculate customer churn, retention, revenue churn, net revenue retention, expected lifetime, and revenue lost to churn.

Inputs

Defaults are visible and can be changed before calculation.

Inline validation messages appear here when a value needs to be corrected.

Calculation mode *Choose customer churn, revenue churn, or both. Currency selection is not required; enter monetary fields in one consistent reporting currency.Period *The period represented by the entered customer or revenue changes.Customers at startStarting customer cohort for the selected period. Required for customer mode.Customers lostCustomers from the starting cohort lost during the period.New customers addedNew customers acquired during the period for net customer change.Recurring revenue at startStarting recurring revenue for the period. Required for revenue mode.Churned recurring revenueRecurring revenue lost from customers who churned.Contraction recurring revenueRecurring revenue lost from downgrades or reduced usage.Expansion recurring revenueRecurring revenue gained from expansion in the existing base.New recurring revenueRecurring revenue from new customers, included in ending recurring revenue but excluded from NRR.Average revenue per customerUsed to estimate revenue lost from customer churn. Enter in the same reporting currency as revenue fields.Gross margin rateUsed to estimate gross profit lost from customer churn.

Results

Results are deterministic scenario outputs, not guarantees.

Enter values and calculate to see the summary, supporting metrics, warnings, and interpretation.

Interpretation

Deterministic interpretation rules will explain what the modeled result means once a calculation is available.

Detailed breakdown

Intermediate calculation rows will appear here after calculation.

Formula

Customer churn

customerChurnRate = customersLost / customersAtStart

Customer retention

customerRetentionRate = 1 - customerChurnRate

Net customer change

netCustomerChange = newCustomersAdded - customersLost

Gross revenue churn

grossRevenueChurnRate = (churnedMrr + contractionMrr) / mrrAtStart

Net revenue retention

netRevenueRetention = (mrrAtStart - churnedMrr - contractionMrr + expansionMrr) / mrrAtStart

Expected lifetime

expectedLifetimePeriods = 1 / customerChurnRate

Assumptions

Customer churn is calculated from the starting cohort, not including new customers added during the period.
Net revenue retention excludes new recurring revenue and includes expansion from the existing revenue base.
New recurring revenue is included in ending recurring revenue but not in NRR.
Currency selection is not applicable; monetary fields should use one consistent reporting currency.

Worked example

Example: customer and revenue retention in one period

If 50 of 1,000 starting customers churn, customer churn is 5% and retention is 95%. If starting recurring revenue is 100,000, with 5,000 churn and contraction and 7,000 expansion, net revenue retention is 102%.

FAQ

Why is new recurring revenue excluded from net revenue retention?

NRR measures the retained and expanded revenue from the existing base, so new customer revenue is included in ending revenue but excluded from the NRR formula.

Why can expected lifetime be undefined?

The simple lifetime formula divides by customer churn. When churn is zero, the formula is undefined rather than a reliable infinite lifetime estimate.

Do I need a currency selector?

No. Use one consistent reporting currency for all monetary inputs; the ratio outputs are independent of currency selection.

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