Plain-English definition
ACOS and TACOS
ACOS is ad spend divided by ad-attributed sales. TACOS is ad spend divided by total sales. Both are ratios; neither replaces a full per-unit profit calculation.
ACOS measures ad-attributed sales efficiency
Advertising cost of sales (ACOS) compares advertising spend with sales attributed to those ads. Sellers use it to assess the efficiency of paid campaigns, but the result depends on attribution and reporting definitions.
TACOS adds total sales context
Total advertising cost of sales (TACOS) compares advertising spend with total sales, including sales not attributed directly to ads. It gives a broader view of advertising spend relative to the business's sales base.
Neither metric is a product profit figure by itself. To assess a sourcing decision, translate a plausible advertising cost into the unit economics and examine how profit changes under different scenarios.
Use both metrics
ACOS tells you how efficient ads are. TACOS shows ad cost relative to all sales and how ads support organic growth.
Include advertising cost per unit in your profit audit so ad spend is not hidden from the result.
Example: the denominator changes the advertising ratio
Illustrative example only: $8 in ad spend divided by $40 in ad-attributed sales is 20% ACOS. The same $8 divided by $80 in total sales is 10% TACOS. The two ratios differ because one uses attributed sales and the other uses total sales.
Neither ratio is product profit. If that $8 spend were allocated across four units sold, the seller-entered ad cost would be $2 per unit for this example; actual attribution and reporting windows depend on the source report.
- ACOS = ad spend ÷ ad-attributed sales; TACOS = ad spend ÷ total sales.
- Compare consistent reporting periods and attribution definitions.
- Convert a planning ratio to per-unit ad cost only with an explicit unit-sales assumption.
Common questions
Frequently asked questions
Which is better, ACOS or TACOS?
They answer different questions. ACOS focuses on attributed advertising sales; TACOS puts ad spend in the context of all sales.
Does a lower ACOS guarantee higher profit?
No. Product costs, organic sales, attribution, discounts, and other expenses also affect profitability.
What is a good ACOS for Amazon sellers?
It should stay below the margin you have after other costs. Compare your ACOS with break-even ACOS to see if ads are profitable.
Ready to check a listing?
Put the assumptions to work.
Bring the visible listing facts and your own costs into a product audit before you commit to inventory.