Formula
If you can afford $40 per acquisition and 2.5% of paid clicks convert, your estimated break-even CPC is $1.00. The result assumes the conversion rate applies to traffic comparable with the traffic you plan to buy.
Use a relevant conversion rate
Brand search, prospecting social and remarketing can convert differently. Use segment-level data instead of a sitewide average when possible. Small samples create unstable CPC limits, so use a longer period or conservative adjustment.
Interpret the result
An average CPC below the threshold does not guarantee profit. Conversion quality, refunds and order value may change by campaign. Monitor the complete funnel and recalculate when the mix changes.
FAQ
Should I bid exactly at break-even CPC?
No. It is a financial ceiling under current assumptions, not a recommended bid. Leave room for volatility and profit.
Does CTR affect the formula?
CTR affects how many clicks impressions produce, but maximum affordable CPC is driven directly by conversion rate and maximum CPA.
Read the break-even CPC guide or calculate maximum CPA first.
Check your complete unit economics
Calculate your break-even ROAS using revenue, product cost, fees, shipping and returns.
Use the Break-even ROAS Calculator