Target CPA Calculator
Calculate a maximum acquisition cost from contribution profit per customer and the profit you want to keep after acquisition.
What this result actually means
Calculate a maximum acquisition cost from contribution profit per customer and the profit you want to keep after acquisition. The page keeps the formula visible—Target CPA = contribution profit per customer − retained profit target.—so you can see exactly which assumption moves the answer instead of treating the calculator as a black box.
The retained-profit input forces a margin of safety into acquisition economics. If you set retained profit to zero, the result becomes a break-even CPA rather than a target that leaves profit after acquisition.
Inputs that control the answer
Business calculators are only as good as the unit economics behind their inputs. Match the numerator and denominator to the same period, traffic source, product mix, or operating scope before interpreting a ratio as a decision signal.
| Input | Example | What to enter |
|---|---|---|
| Revenue per customer ($) | 120 | Use the value that applies to the exact scenario you are modeling; keep its units consistent with the label. |
| Contribution margin (%) | 55 | Enter the percentage as shown, not as a decimal. Use a value tied to the actual policy, history, or scenario you are modeling. |
| Profit to retain after acquisition ($) | 20 | Use the value that applies to the exact scenario you are modeling; keep its units consistent with the label. |
Worked example
Using the example values loaded in the calculator (Revenue per customer = 120, Contribution margin (%) = 55, Profit to retain after acquisition = 20), the browser-side formula produces the outputs below. These are example numbers, not recommended project or business settings.
| Output | Example result |
|---|---|
| Contribution profit per customer | $66.00 |
| Maximum target CPA | $46.00 |
| CPA as share of revenue | 38.3% |
First checkpoint: Contribution profit per customer = $66.00. Change the inputs to your real scenario before using the number for an order, budget, quote, bid, reimbursement, or operating decision.
Where estimates go wrong
- Using revenue where contribution profit is the needed input.
- Mixing gross and net values or different time periods.
- Treating a break-even boundary as a recommended operating target.
The retained-profit input forces a margin of safety into acquisition economics. If you set retained profit to zero, the result becomes a break-even CPA rather than a target that leaves profit after acquisition.
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Questions people run into
How do I calculate a profitable target CPA?
Estimate contribution profit per customer, decide how much profit you want to keep after acquisition, and subtract that retained-profit amount. The remainder is the modeled maximum acquisition cost.
What happens if retained profit is zero?
The result becomes a break-even acquisition cost under the inputs you supplied.
Should target CPA be based on revenue or contribution profit?
Contribution profit is the safer economic basis because revenue still has to pay the variable costs associated with the customer or sale.
Method and limits
Formula: Target CPA = contribution profit per customer − retained profit target.
The calculator runs locally in your browser from the values you enter. The mathematical result is deterministic from those inputs; the planning accuracy depends on whether the inputs represent the real job, route, policy, product, or operating conditions. When the result is close to a purchase threshold, package boundary, safety limit, or financial break-even point, verify the controlling assumption before acting.
Reviewed for calculator depth and clarity · September 2026 · Methodology