How to use the ACOS calculator
Enter advertising spend and the sales attributed to those ads for the same campaign and reporting period. The calculator divides spend by attributed sales and expresses the result as a percentage. It also shows the equivalent ROAS multiple.
ACOS formula
ACOS = Advertising spend ÷ Ad-attributed sales × 100
ACOS shows what percentage of attributed sales revenue is spent on advertising. For example, an ACOS of 20% means $20 was spent on ads for every $100 of attributed sales.
Example: calculate ACOS
If advertising spend is $250 and ad-attributed sales are $2,000, divide $250 by $2,000 and multiply by 100. The result is 12.5% ACOS. The equivalent ROAS is 8.00x because attributed sales are eight times the advertising spend.
ACOS and ROAS relationship
ACOS and ROAS describe the same relationship from different directions. ACOS is a percentage of sales, while ROAS is a revenue multiple. As ACOS decreases, ROAS increases, assuming the same spend and sales figures. Use the ROAS calculator if you prefer to evaluate revenue generated per advertising dollar.
What is a target or break-even ACOS?
Your target ACOS depends on product economics, including gross margin, marketplace fees, fulfillment, discounts, and other variable costs. A break-even ACOS is not a universal industry number: it depends on how much of each sale is available to cover advertising after non-advertising costs. Calculate product profitability before choosing a campaign target.
Frequently asked questions
Is a lower ACOS always better?
A lower ACOS means advertising takes a smaller share of attributed sales, but it may also accompany lower sales volume. Evaluate ACOS alongside total sales, profit, and campaign goals.
Does ACOS include organic sales?
The formula uses sales attributed to advertising, not all business sales. Use the same attribution definition provided by your advertising platform.
Related calculators
- ROAS Calculator – calculate revenue per advertising dollar.
- Ecommerce Profit Calculator – estimate profit after ad and order costs.
- Profit Margin Calculator – calculate gross margin on sales.