Formula
ACoS = Advertising spend ÷ Attributed sales × 100Understanding ACoS
Advertising cost of sales expresses ad spend as a percentage of attributed sales. Spending $4,000 to produce $20,000 of attributed sales gives an ACoS of 4,000 ÷ 20,000 × 100 = 20%.
ACoS is the inverse of ROAS when both use identical inputs: a 20% ACoS corresponds to a 5× ROAS.
What is a good ACoS?
There is no universal target. The acceptable level depends on gross margin, repeat purchases, organic ranking effects and the campaign objective. Compare ACoS with the margin available before advertising rather than with an industry average alone.
Assumptions
- Spend and sales use the same attribution window.
Sources and methodology
CalcMotive publishes the formula and assumptions so you can decide whether the estimate fits your use case. See our methodology standards.