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ACOS calculator: ACOS, TACoS and break-even ACOS for Amazon sellers
· Nolyn research team
Enter your Amazon ad spend, the sales your ads were credited with and your total sales for the same period. The calculator gives ACOS, ROAS, TACoS and the share of sales that came without ads. Then add your price, product cost, FBA fee and referral fee: it works out the break-even ACOS your margin allows, the target ACOS for the profit you want, and what the ads and the whole account earned after ad spend. Everything runs in your browser.
How do you calculate ACOS and TACoS?
ACOS = ad spend ÷ ad sales, TACoS = ad spend ÷ total sales (Amazon Ads definitions, checked October 29, 2026). $1,050 of ads credited with $3,000 in sales is an ACOS of 35% (ROAS 2.86); if the account sold $10,500 in all, TACoS is 10%. A $30 Home and Kitchen item that costs $7.50, with a $6.00 FBA fee and Amazon's 15% referral fee ($4.50), keeps $12.00 before ads: a break-even ACOS of 40%. The ads made $150.00 on their own sales and the account $3,150.00 after ad spend; for a 15% net margin, keep ACOS under 25%.
Calculate ACOS, TACoS and break-even ACOS
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Sponsored Products, Brands and Display spend for the period, from the Advertising console.
Sales Amazon credits to your ads (attributed sales) in the same period.
All ordered product sales for the period, with and without ads (Business Reports). If lower than ad sales, ad sales are used.
What the buyer pays for one unit, before tax.
Landed cost: product, freight to Amazon and duties.
Your item's FBA fulfillment fee from Amazon's Revenue Calculator (it includes the 3.5% surcharge and the October 15 to January 14 peak rates), or your own shipping cost if you fulfill orders.
15% in most categories (Home and Kitchen, Lawn and Garden, Everything Else); check your category on Amazon's pricing page.
Profit left per sale after product cost, fees and ad spend.
- ACOS (ad spend ÷ ad sales)
- 35%
- ROAS (ad sales ÷ ad spend)
- 2.86x
- TACoS (ad spend ÷ total sales)
- 10%
- Sales without ads (organic share)
- 71.4%
- Profit per unit before ads
- $12.00
- Break-even ACOS (your margin before ads)
- 40%
- Target ACOS for 15% net margin
- 25%
- Profit on ad sales after ad spend
- $150.00
- Profit on all sales after ad spend
- $3,150.00
Know your competitors before you raise bids
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ACOS, TACoS and ROAS formulas
Amazon Ads defines ACOS as ad spend divided by ad revenue, shown as a percentage, and ROAS as its inverse. TACoS (total advertising cost of sales) divides the same ad spend by all your sales, organic and paid. Amazon does not show TACoS in a report; take total sales from Business Reports for the same dates as the ad report.
In the example, $1,050 of ads credited with $3,000 in sales gives an ACOS of 35% and a ROAS of 2.86. Total sales were $10,500, so TACoS is 10% and 71.4% of sales came without an ad click.
- ACOS = ad spend ÷ ad sales × 100
- ROAS = ad sales ÷ ad spend = 100 ÷ ACOS
- TACoS = ad spend ÷ total sales × 100
- Break-even ACOS = (price − product cost − FBA fee − referral fee) ÷ price × 100
- Target ACOS = break-even ACOS − the net margin you want
Break-even ACOS is your margin, and cheap items have little of it
Amazon Ads puts the rule plainly: your ACOS needs to be lower than your profit margin to keep a profit. The margin here is before ads: what is left of the price after product cost, the FBA fee and the referral fee. The same cost structure gives very different room for ads at different prices, because the FBA fee is a fixed amount per unit while the referral fee is a percentage:
- At $15, ads must run at an ACOS under 20% just to break even; at $50 the same product can afford 48%.
- Each $0.30 added to the FBA fee of a $30 item takes 1 point off its break-even ACOS. Amazon's holiday peak fulfillment fees run from October 15, 2026 to January 14, 2027, on top of the 3.5% fuel and logistics surcharge in place since April 17, 2026, so recheck your break-even ACOS with the Revenue Calculator before raising bids for Q4.
| Price | Product cost (25%) | Referral fee (15%) | Profit before ads | Break-even ACOS |
|---|---|---|---|---|
| $15.00 | $3.75 | $2.25 | $3.00 | 20% |
| $20.00 | $5.00 | $3.00 | $6.00 | 30% |
| $30.00 | $7.50 | $4.50 | $12.00 | 40% |
| $50.00 | $12.50 | $7.50 | $24.00 | 48% |
Product cost at 25% of the price and a $6.00 FBA fee on every row, for illustration; real FBA fees rise with size and weight. Referral fee 15% (Sell on Amazon pricing page, checked October 29, 2026).
Why TACoS matters more than ACOS
ACOS judges ads only on the sales Amazon credits to them. Amazon Ads' own holiday guide makes the point: ACOS often rises when traffic and competition peak, and TACoS shows whether total sales, organic and paid, are growing in relation to ad spend. A falling TACoS means the ads are helping the listing sell on its own.
In the example the ads made only $150.00 after ad spend on their own sales (40% margin on $3,000, minus $1,050), but the account made $3,150.00. Hold the ad spend at $1,050 and watch what organic growth does:
- The ceiling for TACoS is the same as for ACOS: your margin before ads minus the net margin you want (25% here). Above 40%, the account loses money.
- A launch can run a high ACOS on purpose to win reviews and rank; judge it by whether TACoS falls over the following weeks.
| Total sales | TACoS | Profit after ad spend (40% margin) |
|---|---|---|
| $10,500 | 10% | $3,150.00 |
| $14,000 | 7.5% | $4,550.00 |
| $21,000 | 5% | $7,350.00 |
Same $1,050 ad spend and $3,000 in ad sales; only organic sales change. Profit after ad spend = total sales × 40% − $1,050.
What is a good ACOS?
Amazon Ads does not give one: it depends on your margin, category and goals. A useful answer is two numbers from this calculator. An ACOS below your target ACOS (break-even minus the profit you want) is profitable on its own. An ACOS between target and break-even is profitable but thin. Above break-even, the ads lose money on their own sales and need organic lift to justify them.
To see how the same math works across channels (Google Shopping, TikTok Shop ads), use the break-even ROAS calculator and the ROAS calculator. If customers buy more than once, the customer acquisition cost calculator shows what a new customer is worth beyond the first order.
How to use the ACOS calculator
Pull the ad report
Ad spend and attributed sales for the period from the Amazon Ads console.
Add total sales
Ordered product sales for the same dates from Business Reports, to get TACoS.
Enter your unit economics
Price, landed cost, FBA fee from the Revenue Calculator and your category's referral fee.
Compare ACOS with break-even and target
Set bids so ACOS stays under the target, and track TACoS week by week.
Questions
What is the ACOS formula?
ACOS = ad spend ÷ ad sales × 100. $1,050 of ad spend credited with $3,000 in sales is an ACOS of 35%.
What is TACoS on Amazon?
Total advertising cost of sales: ad spend ÷ total sales, organic and paid. $1,050 of ads in a month with $10,500 of total sales is a TACoS of 10%. Amazon does not report it; divide the ad spend by ordered product sales from Business Reports.
What is break-even ACOS?
Your profit margin before ads. A $30 item that costs $7.50, with a $6.00 FBA fee and a 15% referral fee, keeps $12.00, so its break-even ACOS is 40%. Above that, the ads lose money on the sales they bring.
What is the difference between ACOS and ROAS?
They are the same ratio upside down: ROAS = ad sales ÷ ad spend = 100 ÷ ACOS. An ACOS of 35% is a ROAS of 2.86.
What is a good ACOS on Amazon?
One below your break-even ACOS minus the profit you want. With a 40% margin before ads and a 15% net margin goal, a good ACOS is under 25%. There is no single figure for all sellers, because margins differ.
Is a high ACOS always bad?
No. During a launch or Q4, ACOS can rise while TACoS falls, because the ads lift organic rank and sales. Amazon Ads recommends looking at TACoS before pulling back when ACOS rises in high-traffic periods.
Sources
- Amazon Ads: What is advertising cost of sales (ACOS)? Calculation and tips (ACOS = ad spend ÷ ad revenue × 100; ROAS is its inverse; your ACOS needs to be lower than your profit margin to keep a profit) · checked October 29, 2026
- Amazon Ads: Holiday advertising myths (ACOS only measures ad-attributed sales; total advertising cost of sales, TACOS, shows whether total sales, organic and paid, grow in relation to ad spend) · checked October 29, 2026
- Sell on Amazon: Pricing (referral fee 15% with a $0.30 minimum in Home and Kitchen, Lawn and Garden and Everything Else; total sales price includes shipping and gift wrap) · checked October 29, 2026
- Amazon Seller Central (US): FBA fulfillment fee (per-unit fee by product type, size tier and shipping weight; 3.5% fuel and logistics surcharge since April 17, 2026; holiday peak fees October 15, 2026 to January 14, 2027) · checked October 29, 2026