Retail Media ACoS & ROAS Comparator
This tool calculates and compares Advertising Cost of Sale and Return on Ad Spend across multiple retail media networks simultaneously, so you can evaluate performance consistency or identify where your spend is working hardest. It is built for e-commerce managers and retail media buyers who run campaigns across Amazon Ads, Walmart Connect, Kroger Precision Marketing, or other networks and need a single view of cross-network efficiency. The side-by-side comparison makes it straightforward to present channel efficiency to stakeholders without building a custom spreadsheet.
Inputs
Results
How this is calculated
Enter your ad spend and attributed revenue for each retail media network, and the tool calculates ACoS (ad spend divided by attributed sales) and ROAS (attributed revenue divided by ad spend) for each, displaying them side by side with a performance comparison.
Every model runs locally in your browser. Nothing you type is sent anywhere.
Frequently asked questions
What is ACoS and how is it different from ROAS?
ACoS, or Advertising Cost of Sale, expresses ad spend as a percentage of attributed revenue. A 20% ACoS means you spent $20 in ads for every $100 in sales. ROAS, or Return on Ad Spend, is the inverse expressed as a ratio or multiplier — a 5x ROAS means you generated $5 in sales for every $1 spent. Both metrics measure the same relationship; which one you use is largely a matter of industry convention, with ACoS common in Amazon-first contexts and ROAS more prevalent elsewhere.
What is a good ACoS for retail media?
A good ACoS depends on your product's margin structure. The breakeven ACoS is your gross margin percentage — if your product has a 40% gross margin, an ACoS at or below 40% means advertising is not eroding profitability. Many retail media practitioners target an ACoS of 15 to 25% for established products to ensure advertising contributes positive margin. New product launches or brand-building campaigns often accept higher ACoS temporarily in exchange for sales velocity and organic ranking gains.
How do I compare performance across different retail media networks?
The most useful comparison normalizes for attribution windows and attribution models, which differ across networks. Amazon's default last-click 14-day attribution window will produce different reported ROAS numbers than Walmart's attribution model even for identical campaign performance. This comparator shows the numbers you report into each platform, which is the operationally relevant view, but note that cross-network comparisons should be interpreted with awareness of these methodological differences.