Max CPA & CPC Calculator
Translate margin targets into the highest CPA you can afford and the max CPC your bidding strategy should be told to chase. Useful for Google Ads, Meta, and Performance Max bid caps.
Your unit economics
Revenue minus COGS / fulfillment / payment processing — what is left to spend on ads + profit.
Margin remaining after ad spend. 15–25% is typical eComm; lower for subscription / high-LTV.
Click → conversion, not session → conversion. Pull from GA4 → User Acquisition.
$0.75
Use this as the upper bound for Max CPC bid limits and PMax bid caps. Break-even ceiling is $1.35 — anything above that loses money on every click at this CR.
Gross per order
$54.00
Available for ads + profit.
Max CAC (target margin)
$30.00
Set Target CPA in Google Ads to this.
Target ROAS
4.00×
For tROAS bidding strategies (1× = 100%).
Break-even CAC
$54.00
0% margin ceiling. Above this you lose money.
Reminder: max CPC ≈ max CAC × CR. If your ROAS reporting is missing 30% of conversions, your real conversion rate is higher and you can bid more aggressively than the platform suggests — but only if attribution is fixed.
Pair this with the Attribution Recovery Calculator to see the gap.
