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Target CPA from LTV Calculator
Translate LTV and contribution margin into a target CPA (and break-even CPA) for paid acquisition.
A 'good' CPA depends on how much value a customer creates. Target CPA connects acquisition cost to unit economics so you can scale profitably.
This calculator computes break-even CPA from LTV and contribution margin, and also a target CPA based on desired profit buffer or payback fraction.
Prefer an explanation- Read the guide.
Target CPA: how to set acquisition targets from LTV and marginPaid ads bidding & budgeting hub: max CPC, target CPA, and break-even targetsCAC vs CPA: definitions, formulas, and when to use eachMax CPC and break-even CPC: how to set bidding targets from margin
If you already have gross profit LTV, set margin to 100%.
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Profit buffer as % of gross profit LTV (e.g., 20% means spend <= 80% of gross profit LTV).
%
If you prefer a simple rule: set a max share (e.g., 50%). 0 disables.
%
Tip: you can type commas (e.g., 10,000).
Example
Using the default inputs, the result is:
$1,440.00
- Revenue LTV (lifetime revenue)
- $3,000
- Contribution margin
- 60%
- Target profit buffer (optional)
- 20%
- Max spend as % of gross profit LTV (optional)
- 0%
How to calculate
- Enter gross profit LTV (or revenue LTV and margin).
- Choose how conservative you want to be (target profit buffer or spend as % of LTV).
- Use break-even and target CPA to set bidding/optimization targets.
Formula
Gross profit LTV = revenue LTV x contribution margin; Break-even CPA = gross profit LTV; Target CPA = break-even x (1 - buffer) or x spend share
- LTV is measured on a consistent basis with your CPA attribution window.
- Contribution margin reflects variable costs (not fixed overhead).
- Incrementality may be lower than attribution; validate with experiments when possible.
FAQ
Should I use CAC or CPA-
CPA is often used at the campaign level (purchase/lead). CAC usually means cost per new paying customer. Use the denominator that matches your funnel stage and label it clearly.
Why set a target below break-even-
Because forecasts are uncertain and you usually need buffer for returns, fraud, attribution bias, and overhead. A target CPA below break-even reduces the risk of scaling into losses.
Common mistakes
- Using revenue LTV instead of gross profit LTV (overstates value).
- Ignoring cash/payback constraints (long payback can kill runway).
- Using platform-attributed LTV without incrementality validation.
Related calculators
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ROAS Calculator
Calculate Return on Ad Spend (ROAS) and estimate contribution profit after ad spend.
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Break-even ROAS Calculator
Estimate the break-even ROAS based on contribution margin assumptions.
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Target ROAS Calculator
Estimate a target ROAS to cover variable costs plus a desired margin buffer.
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Paid Ads Funnel Calculator
Model CPM -> CTR -> CVR to estimate CPC, CPA, ROAS, and profit per 1,000 impressions (with margin and variable costs).
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ROI Calculator
Calculate Return on Investment (ROI) for a campaign or project.
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Incrementality Lift Calculator
Estimate incremental conversions, incremental ROAS, and incremental profit from a holdout test.
Quick checks
- Keep attribution model and window consistent when comparing campaigns.
- Pair efficiency metrics (ROAS/CPA) with profit assumptions (margin, refunds, fees).
- Validate tracking after site changes (pixels/events can silently break).