How to Set Target CPA

Your target CPA (cost per acquisition) should never exceed what you keep per conversion after product or fulfillment costs. That ceiling is your max CPA — the highest you can pay and still break even on ad spend.

The formula

Max CPA = (value × gross margin %) − fixed cost per conversion

Ecommerce: value is AOV per purchase. Lead gen: use customer value × close rate as expected revenue per lead, and fixed cost per lead.

Ecommerce example

  • AOV = $90
  • Gross margin = 50%
  • Fixed cost per order = $6 (shipping + payment fees)

Contribution = ($90 × 50%) − $6 = $39

Target CPA: $39 — enter this as your target cost per purchase in Google Ads or benchmark Meta cost per purchase against it.

Lead gen example

  • Customer value = $5,000
  • Close rate = 15%
  • Gross margin = 60%
  • Fixed cost per lead = $0

Expected revenue per lead = $5,000 × 15% = $750

Contribution per lead = $750 × 60% = $450

Target cost per lead: $450 in your ad platform.

CRM closed-deal cap: $450 ÷ 15% = $3,000 max cost per closed deal.

Where to set target CPA

  • Google Ads: Target CPA bidding or manual CPA caps in campaign settings — compare actual cost per conversion to your max.
  • Meta Ads: Cost per result (purchase or lead) vs your calculated cap; use as a reporting benchmark even on ROAS campaigns.
  • Lead gen CRM: Track cost per lead in ads and cost per closed deal in CRM separately — they use different denominators.