Amazon ACOS Calculator — break-even ACOS, TACOS and ROAS in one free tool
Most Amazon sellers scale Sponsored Products without knowing their break-even ACOS. This free Amazon ACOS calculator uses your selling price, COGS, FBA fulfilment fee and referral fee to show the exact ACOS you can afford — plus target ACOS, ROAS and the TACOS trend that proves your brand is growing organically.
The ACOS formula
ACOS % = Ad Spend ÷ Ad-Attributed Sales × 100 Break-even ACOS % = (Price − COGS − FBA fee − Referral fee) ÷ Price × 100 Target ACOS % = Break-even ACOS − Desired net margin % ROAS = Ad-Attributed Sales ÷ Ad Spend TACOS % = Ad Spend ÷ Total Sales × 100
Worked example — calculating Amazon ACOS
$29.99 price, $6 COGS, $4.50 FBA fee, 15% referral ($4.50). Gross profit = $15 / $29.99 = 50% gross margin, so break-even ACOS is 50%. Target a 15% net margin → target ACOS = 35%. Ads running at 22% ACOS deliver ~13% net profit before overhead.
How to lower ACOS on Amazon fast
- Kill keywords running 3× above your target ACOS in 30-day windows
- Move top converters to exact match with higher bids and dayparting
- Fix listing conversion — better title, main image, bullets, A+ content
- Add negative keywords aggressively (irrelevant search terms drain budget)
- Split branded vs non-branded campaigns so branded ACOS doesn't hide the real number
ACOS vs TACOS vs ROAS — quick reference
- ACOS — ad efficiency for a single campaign or ad group
- TACOS — total ad efficiency including organic sales (brand health)
- ROAS — the inverse of ACOS (ROAS = 1 ÷ ACOS × 100)
What is a good ACOS by product category?
- Private label FBA (25–40% margin): target ACOS 15–25%
- Wholesale / resale (10–20% margin): target ACOS 5–12%
- Handmade / high-margin niche (50%+ margin): target ACOS 25–40%
- New launch phase: run at break-even ACOS to buy organic rank
Related free seller tools
Pair with the Amazon FBA Calculator, Amazon Listing Title Builder, Shopify Break-even ROAS Calculator and the Profit Margin Calculator. Browse the full free seller tools directory.