What is ACOS? Amazon Advertising Cost of Sales
Quick Definition
ACOS (Advertising Cost of Sales) is the percentage of ad spend relative to attributed sales revenue. An ACOS of 25% means you spent $25 in ads to generate $100 in sales.
Calculating ACOS
ACOS = (Total Ad Spend ÷ Total Ad Revenue) × 100. If you spent $50 on ads and generated $200 in sales from those ads, your ACOS is 25%. This is the inverse of ROAS (Return on Ad Spend) — a 25% ACOS equals a 4x ROAS. Amazon displays ACOS in your Campaign Manager dashboard.
What's a Good ACOS?
Target ACOS depends on your profit margin. If your profit margin before ads is 35%, any ACOS below 35% is profitable (this is your "break-even ACOS"). Most sellers aim for 15–25% ACOS on established products. New product launches often run 40–60% ACOS intentionally to gain ranking and reviews — this is a strategic investment, not waste.
ACOS vs TACoS
TACoS (Total Advertising Cost of Sales) measures ad spend against total revenue, including organic sales. While ACOS only counts ad-attributed sales, TACoS shows the true impact of advertising on your overall business. As your organic ranking improves, TACoS decreases even if ACOS stays the same — a sign your ads are driving sustainable growth.
Lowering Your ACOS
Key strategies: optimize targeting by adding negative keywords, focus budget on high-converting exact match terms, improve listing quality (better images and copy increase conversion rate, which lowers ACOS), adjust bids based on placement performance, and use automated bidding rules. Also consider product pricing — a slightly higher price improves ACOS even with the same ad spend.
ACOS Calculator Tools
Helium 10's Adtomic, Jungle Scout's Advertising Analytics, Perpetua, Quartile, and Pacvue all offer ACOS tracking within their paid PPC management suites. For quick calculations, AstroMarket's free ACOS Calculator computes your ACOS, ROAS, TACoS, break-even ACOS, and per-unit profit — with a visual gauge showing whether your campaigns are profitable, marginal, or losing money.
Related Terms
Amazon PPC
Amazon PPC is Amazon's advertising system where sellers bid on keywords to show sponsored product listings in search results. You pay only when a shopper clicks your ad.
Keyword Research
Keyword research is the process of finding the search terms customers use to find products. Optimizing your listing for the right keywords increases visibility and sales.
Amazon FBA
FBA (Fulfillment by Amazon) is a service where Amazon stores your products, picks, packs, and ships orders to customers, and handles customer service and returns.
Profit Margin
Profit margin is the percentage of revenue that remains as profit after subtracting all costs. For e-commerce, this includes product cost, platform fees, shipping, and advertising.
ACOS Calculator
An ACOS calculator computes your Advertising Cost of Sales, ROAS, TACoS, and break-even ACOS to determine whether your Amazon PPC campaigns are profitable.
Put ACOS data to work
AstroMarket analyzes acos alongside competition, trends, sourcing costs, and social signals — all in one AI-powered report.