How to use the churn rate calculator
Enter customer counts or revenue amounts for one period, then choose how to label the calculation. The result shows gross churn, retention, net churn, net retention, and growth rates, along with the formula, assumptions, and intermediate values used.
Enter values for one period
- Choose Customer churn (count) or Revenue churn (amount) from Churn type.
- Choose Monthly, Quarterly, Annual, or Custom period from Period. This label appears in the result and downloaded summary; all four figures must cover the same period.
- In Revenue churn (amount), choose a value from Currency symbol. The choice changes the display label only; it does not convert the amount.
- Enter Starting customers (period start) and Lost customers (churned during period). Starting must be greater than 0. Lost can be 0 or more, but cannot exceed Starting.
- Optionally enter New / gained customers (during period) and Ending customers (period end) - optional. Each entered optional value must be 0 or more. A blank gained value counts as 0, and a blank ending value is calculated.
- Select Calculate churn. Select Reset to clear the fields and result.
Revenue churn (amount) changes the field labels from customers to revenue. A blank or invalid required value, an invalid optional value, or Lost greater than Starting produces an error and keeps the result hidden.
Customer churn calculator and revenue churn calculator formulas
Customer churn uses counts. Revenue churn uses an amount, with the selected Currency symbol shown beside it. The same formulas apply in both modes.
Starting customers: 1000
Lost customers: 50
New / gained customers: 20
Ending customers: blank
Gross churn rate: 5.00%
Net churn rate: 3.00%
Implied ending customers: 970Gross churn rate = Lost / StartingRetention rate = 1 - Gross churn rateNet churn rate = (Lost - Gained) / StartingNet retention rate = 1 - Net churn rateGrowth rate = (Ending - Starting) / Starting
The result includes these rates, an assumptions table, and intermediate values. An entered Ending value determines growth rate. When Ending is blank, the calculator uses Starting - Lost + Gained.
What the ending value warning means
When you enter Ending customers or revenue, the calculator compares it with Starting - Lost + Gained. It shows a warning when the difference is greater than the larger of 0.5% of Starting and the floor for that mode, 0.5 for customer churn or 0.01 for revenue churn.
The warning leaves the result visible. Churn and retention use Starting, Lost, and Gained. Growth uses the Ending value you entered, so the result shows both the movement-based figures and the recorded period-end figure.
Check a recorded ending value
Leave Ending customers (period end) - optional blank when the implied total is the figure you need. Enter a recorded period-end total when you want the calculator to compare it with Starting - Lost + Gained and show a warning when the difference crosses the tolerance.
After the calculation appears, select Copy result to copy the summary or Download result (.txt) to save it as churn-rate-calculator-result.txt.
When another business calculator fits better
Use Business Calculators for a different business metric. Choose the MRR Calculator for a movement report using starting MRR, new MRR, expansion, contraction, and churned MRR. Choose the ARR Calculator to calculate annual recurring revenue from recurring revenue and billing period.
Choose the Cash Runway Calculator when you need a month-by-month runway projection based on cash balance, revenue, and burn assumptions.
Frequently asked questions
How do I calculate churn rate with the churn rate calculator?
Gross churn rate is Lost divided by Starting, shown as a percentage. Net churn rate is (Lost - Gained) divided by Starting. Retention rate is 1 minus gross churn rate.
Can I use this as a customer churn calculator?
Choose Customer churn (count), then enter customer counts for the same period. The field labels and assumptions table use customer counts.
How does a revenue churn calculator handle currency?
Choose Revenue churn (amount), then select Currency symbol. The symbol changes the display label only. The calculator does not convert the amount.
Why does my ending value trigger a churn calculator warning?
The warning appears when your entered Ending value differs from Starting - Lost + Gained by more than the calculator's tolerance. The result remains visible. Growth uses your entered Ending value.
Does the churn rate calculator use live customer or revenue data?
The calculator uses only the values you enter and performs the arithmetic locally in your browser. It does not fetch CRM, billing, or other external data.