ACoS / ROAS Calculator
Is your ad spend worth it? Enter ad spend and resulting sales to instantly evaluate ad efficiency.
| ACoS Range | Evaluation | Recommendation |
|---|---|---|
| < 15% | Excellent | Can moderately increase bids to scale |
| 15%–30% | Good | Maintain status quo, keep optimizing keywords |
| 30%–45% | Warning | Review keyword bids promptly |
| > 45% | Loss | Pause inefficient keywords, lower bids |
Advertising Cost of Sale (ACoS) and Return on Ad Spend (ROAS) are the two most widely used metrics for measuring Amazon advertising efficiency. ACoS is your ad spend as a percentage of the revenue it generated; ROAS is the inverse—revenue generated per dollar of ad spend. Understanding these metrics in relation to your product's profit margin is essential: an ACoS that looks moderate in isolation can still mean your ads are unprofitable if your margin is thin. This free ACoS / ROAS calculator takes your ad spend, resulting sales, and product margin, then computes both metrics and tells you definitively whether your current advertising is profitable, breaking even, or generating a net loss. Use it to evaluate campaigns, set bid targets, and build a sustainable advertising strategy.
ACoS vs. ROAS: Understanding Both Metrics
ACoS is calculated as: ACoS (%) = Ad Spend ÷ Ad-Attributed Sales × 100. ROAS is the reciprocal: ROAS = Ad-Attributed Sales ÷ Ad Spend. A $100 ad spend generating $500 in sales means an ACoS of 20% and a ROAS of 5. The critical insight is that your target ACoS should equal your product's gross profit margin—at that point, advertising is precisely breaking even at the product level. An ACoS below your margin means ads are profitable; an ACoS above your margin means each attributed sale is generating a net loss on advertising. For example, if your gross margin is 35% and your ACoS is 28%, your net margin after advertising is roughly 7%. If your ACoS climbs to 40%—above your 35% margin—every ad-attributed sale costs you 5 percentage points. ROAS framing is common in agency reporting because higher is always better (unlike ACoS, where lower is better), making performance look more flattering. Both metrics represent the same underlying ratio.
Target ACoS and Suggested Maximum Bid
Setting a target ACoS gives you a concrete optimization anchor. Your target ACoS should typically equal your gross profit margin—the point at which ad spend is exactly paid for by advertising-generated profit. More aggressive targets (ACoS 5–10% below margin) build profitability cushion. More aggressive growth targets may accept ACoS near or slightly above margin to gain ranking and organic velocity, then optimize as volume grows. The suggested maximum bid is a derived metric: Maximum Bid ≈ Average Order Value × Profit Margin (%) ÷ 100 × Estimated Conversion Rate. With a 3% assumed conversion rate (a reasonable Amazon average for many categories), a $50 product with a 30% margin yields a suggested bid of $0.45 ($50 × 0.30 × 0.03). This is a starting point—actual bid optimization requires campaign-level data and keyword-level conversion rates. Broad match keywords typically convert at lower rates and require lower bids; exact match and product targeting often achieve higher conversion rates and can support higher bids.
Practical Strategies to Improve ACoS
Improving ACoS is not simply about cutting bids—it requires a systematic approach across the full advertising funnel. On the keyword level: pause keywords with high spend and zero or few conversions; reduce bids on keywords with ACoS significantly above target; scale bids on profitable keywords. On the listing level: a strong listing converts better at the same click cost, directly lowering ACoS—test main image, title, and price. On the campaign structure level: exact match campaigns for proven keywords keep quality traffic tight; broad and phrase match campaigns for discovery should have lower bids and tighter negative keyword lists. Seasonal patterns matter: Q4 cost-per-click on Amazon averages 30–50% higher than Q1, temporarily pushing ACoS up without any change in bid strategy. Factor this into your targets. Finally, consider the full-funnel effect—some Sponsored Brand and Display traffic generates organic ranking uplift that does not appear in attributed sales, meaning true advertising ROI may exceed what ACoS reports for brand-building campaigns.
How to Use the ACoS / ROAS Calculator
- Enter your total ad spend for the period you want to evaluate—this should match the spend reported in your Amazon Advertising or other platform dashboard.
- Enter the sales revenue directly attributed to those ads over the same period—use the 'Sales' column in your Amazon campaign report (not total store sales).
- Enter your product gross profit margin percentage—this is your selling price minus all direct costs (product cost, shipping, FBA fee) divided by selling price.
- Enter the number of clicks your campaign received if you want a suggested maximum bid calculation.
- Review ACoS vs. your margin: if ACoS is below margin, advertising is profitable; if above, each ad-attributed sale generates a net loss. Use the tiered evaluation table to plan your next optimization action.