Free customer acquisition calculator
Customer Acquisition Cost Calculator
Calculate customer acquisition cost, gross-margin-adjusted contribution LTV, LTV:CAC, and estimated payback using only the numbers you enter.
Keep acquisition cost and customer contribution in one model.
CAC is acquisition spend divided by new customers from the same stated period. Monthly contribution is monthly sales per customer multiplied by gross margin. Contribution LTV directly multiplies monthly sales, gross margin, and average customer lifetime before rounding that result to cents.
LTV:CAC divides contribution LTV by CAC. Estimated payback divides CAC by monthly contribution. The optional maximum CAC divides contribution LTV by the target ratio you enter; the calculator does not choose a target for you.
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Use one period and your own inputs.
Choose one acquisition period from your records, such as the last 30 days or last quarter. Use that same period for spend and new customers. Nothing here selects a benchmark or sends your entries to an AI service.
Calculated result
Enter valid inputs to calculate the model.
Results stay in this page until you reset, edit an input, or leave. The calculator does not fetch, save, or send input values.
Round money first, then calculate the ratios.
The calculator rounds CAC, monthly contribution, and contribution LTV independently to cents. It then uses those displayed cents for LTV:CAC, payback, and the optional target calculation. Ratios and months display two decimal places, with halfway values rounded up.
Choose one acquisition period
Use the same period and attribution scope for acquisition spend and new customers.
Calculate CAC
Divide acquisition spend by new customers acquired in that period.
Calculate contribution LTV
Multiply monthly sales per customer by gross margin and average customer lifetime in months, then round the result to cents.
Compare ratio and payback
Divide contribution LTV by CAC for LTV:CAC, and divide CAC by monthly contribution for estimated payback months.
One stated month, shown step by step.
Illustrative inputs only: $6,000 in acquisition spend and 30 new customers in one month produce a $200 CAC. Monthly sales of $100 at an 80% gross margin produces $80 in monthly contribution. An 18-month lifetime produces $1,440 in contribution LTV.
Those inputs produce an LTV:CAC of 7.20:1 and estimated payback of 2.50 months. If the user enters a 3.00:1 target, maximum CAC at that target is $480. These outputs describe the example; they do not establish a benchmark or predict an outcome.
The arithmetic can be exact while the inputs are uncertain.
The model does not verify attribution, cost completeness, customer definitions, refunds, discounts, churn timing, collection timing, or whether one cohort represents another. It does not discount future contribution or forecast demand, growth, sales, profit, or business value.
Compare cohorts only when their period, spend scope, customer definition, margin method, and lifetime method match. Treat a zero-spend result as a prompt to check whether acquisition cost was omitted, not as proof that acquisition is free.
Answers to common CAC, LTV, and payback questions.
How do I calculate customer acquisition cost, LTV:CAC, and CAC payback?
Foundable's Customer Acquisition Cost Calculator divides acquisition spend by new customers from the same period for CAC. It multiplies monthly sales per customer by gross margin and average lifetime for contribution LTV, then calculates LTV:CAC, estimated payback months, and an optional maximum CAC at a user-entered target ratio. It uses no default benchmark and does not forecast an outcome.
How do I calculate customer acquisition cost?
Choose one period and divide the sales and marketing spend attributed to acquisition in that period by the number of new customers acquired in the same period. If there are no new customers, CAC cannot be calculated for that period.
How does this calculator calculate customer LTV?
Monthly contribution equals monthly sales per customer multiplied by gross margin. Contribution LTV multiplies monthly sales per customer by gross margin and average customer lifetime directly, then rounds that result to cents.
How are LTV:CAC and CAC payback calculated?
LTV:CAC equals contribution LTV divided by CAC. Estimated payback months equals CAC divided by monthly contribution. A zero denominator makes the affected result unavailable rather than infinite.
Does the calculator assume a target LTV:CAC ratio?
No. The target ratio is optional and user-entered. When provided, maximum CAC at that target equals contribution LTV divided by the target ratio. The calculator does not label any ratio as good or predict an outcome.
Turn the result into one bounded acquisition test.
Use one audience, one channel, one spend limit, one attribution period, and one learning goal. Keep actual customer behavior separate from the planning assumptions in this calculator.