CPA Calculator

$
$
$
Finance

Calculate Cost Per Acquisition (CPA) — the average cost to acquire one customer from an advertising campaign.

Formula

CPA = Total Ad Spend ÷ Conversions; ROAS = Revenue ÷ Ad Spend
  • A 'conversion' is a desired action: purchase, sign-up, lead, etc.
  • ROAS: a 3× ROAS means you earn $3 for every $1 spent on ads.
  • Target CPA should be less than your average order value minus COGS.

$5,000 spend, 125 conversions

Inputs
  • Total Ad Spend: 5000 $
  • Number of Conversions: 125
  • Revenue Generated: 18750 $
  • Cost of Goods Sold: 9375 $

CPA = $5,000/125 = $40. Revenue/conv = $150. ROAS = 3.75×. Gross profit = $4,375.

Frequently asked questions

What is a good CPA?
CPA depends on your product price and margin. Target CPA = Customer Lifetime Value × acceptable margin.
What is the difference between CPA and CPC?
CPC (cost per click) measures ad clicks; CPA measures completed conversions (much more meaningful).
What is target CPA bidding?
A Google Ads bidding strategy where the algorithm automatically adjusts bids to hit your target CPA.
How do I lower my CPA?
Improve landing page conversion rates, refine audience targeting, test ad creatives, and optimize keyword bids.