Unit economics calculator.
Connect customer acquisition cost, monthly contribution, churn, and payback. Test the assumptions behind a subscription business.
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Know what a customer contributes.
Model a subscription business with a steady monthly price, delivery cost, churn rate, and acquisition spend.
Recurring revenue per paying customer in the same monthly period.
Costs of delivering the service to one customer. Excludes acquisition spend and fixed overhead.
Share of customers lost in a month. Enter 5 for 5%; use customer churn, not revenue churn.
Sales and marketing spend attributed to the period that produced these new customers.
Customers acquired from that spend and period. Enter a whole number.
All money amounts are in US dollars (USD). Change the illustrative starting values to fit your business.
- Monthly contribution per customer
- $70.00 Revenue less variable delivery cost. Gross margin: 70%.
- Customer acquisition cost
- $300 Acquisition spend divided by new customers in the same period.
- Simple contribution LTV
- $1,400 A constant-churn estimate before fixed overhead and discounting.
- Simple CAC payback
- 4.29 months Assumes the customer remains active; this is not churn-adjusted recovery.
- Contribution LTV / CAC
- 4.67× Compare with your retention evidence and cash constraints.
- Monthly revenue
- $100
- Variable delivery cost
- $30.00
- Contribution
- $70.00
All bars use the same scale. The vertical line marks zero.
View comparison data
| Item | Value |
|---|---|
| Monthly revenue | 100 |
| Variable delivery cost | 30 |
| Contribution | 70 |
Contribution is the amount left after the entered variable delivery cost. Fixed overhead and acquisition cost are excluded from this monthly comparison.
Each active customer contributes toward acquisition cost and fixed overhead in this scenario. A longer estimated lifetime does not guarantee that customers will stay or that the business will generate a profit.
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Useful numbers.
Clear assumptions.
Monthly contribution = ARPA − variable delivery cost · CAC = acquisition spend ÷ new customers · Simple contribution LTV = monthly contribution ÷ monthly churn
ARPA means average monthly revenue per account. The LTV approximation assumes a stable monthly churn rate, unchanged revenue and delivery cost, and no expansion revenue, discounting, taxes, or fixed overhead. It estimates a contribution stream, not net profit or an independently measured customer lifetime.
Simple payback is CAC divided by monthly contribution. It assumes an ongoing active customer and does not model churn-adjusted cohort cash recovery. Acquisition spend and new customers must cover the same period and attribution basis. These are planning assumptions, not a valuation or an investment recommendation.
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