Cost per acquisition (or cost per action, or cost per result in Meta) is the number most ad accounts should be judged on.
How to calculate CPA
CPA = spend ÷ conversions
It breaks down into three parts: CPA = CPM ÷ (CTR × conversion rate × 1,000). Cheaper impressions, more clicks or better conversion all lower it.
What's a normal CPA on Meta?
Across US accounts spending $100K+ (mid-July to mid-October 2026), the median cost per purchase for ecommerce brands was $58, with a range of $17 to $374. The median cost per lead was $40. The median brand's cost per purchase was 46% of its average order value.
What actually moves it
Within each brand, post-click conversion rate explained about 85% of the difference in cost per purchase between ads. CPM explained about 20%. CTR explained close to none.
Full data: Facebook ads cost and what predicts cost per purchase.
