Payback calculators
LTV:CAC Calculator
Built the growth engine that took cnvrg.io to its acquisition by Intel.
Is each customer worth what you pay to acquire them? Compare lifetime gross profit with CAC using your own revenue, margin and churn; the formulas are on the page.
LTV:CAC calculator
Compare the gross profit a customer brings over its lifetime with what it cost to acquire.
Gross-profit lifetime value against acquisition cost, from your inputs.
How this is calculated
Monthly gross profit = ARPA × gross marginLTV = monthly gross profit ÷ monthly churn (with a cap: the surviving gross profit summed over the capped months)LTV:CAC = LTV ÷ CAC
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What LTV:CAC answers
LTV:CAC compares the gross profit a customer is expected to bring over its lifetime with the cost of acquiring that customer. It answers whether growth creates value or only revenue.
How the calculator works
Monthly gross profit is revenue per customer (ARPA) times gross margin. Lifetime value is that monthly gross profit divided by monthly customer churn. Add a lifetime cap and the calculator counts only the gross profit of customers still active up to that month. The ratio is lifetime value divided by CAC. It also shows the CAC payback in months.
A worked example with hypothetical numbers
At 500 a month per customer and an 80% gross margin, a customer returns 400 a month. With 2% monthly churn the expected lifetime is 50 months, so lifetime value is 400 ÷ 0.02 = 20,000. Against a CAC of 5,000 the ratio is 4 to 1, and payback is 12.5 months. These numbers illustrate the arithmetic; they are not a benchmark or a client result.
What the result does not tell you
A constant churn rate rarely holds for young cohorts, and zero churn makes the lifetime unbounded, so the calculator asks for a cap instead of showing infinity. Expansion revenue and price changes are not modelled. Use cohort data when you have it.
Turn the result into a next step
Compare the ratio by segment and channel, not only blended, and check how long CAC takes to come back with the CAC payback calculator. For SaaS unit economics work, see B2B SaaS growth.
LTV:CAC questions
Why gross profit and not revenue?
Revenue overstates what a customer is worth, because serving the customer costs money. Using gross margin makes LTV comparable with the cash spent on CAC.
What if churn is zero?
Then lifetime value has no upper bound, so the calculator asks for a lifetime cap in months instead of reporting infinity.
What LTV:CAC ratio should I aim for?
This calculator does not impose a target. Compare the ratio with your payback period, your cash position and the cohorts behind it.
Does the calculator store or send my numbers?
No. It runs in your browser. Nothing is sent unless you choose to send the result to me, and a share link keeps your numbers after the # sign, which browsers do not send to this site.
Can an AI agent run this calculator?
Yes. The same calculation is available as the run_calculator tool on this site's MCP server and at GET /api/v1/calculators?id=ltv, with the same inputs, formulas and limits as this page.
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I personally review the numbers behind the result, agree the scope with you and deliver the work. Bring the questions the calculator raised.