Amazon ACoS & TACoS Calculator
Enter your ad spend, ad-attributed sales, total sales, and product gross margin to instantly see your ACoS, TACoS, ROAS, and the break-even ACoS ceiling that tells you whether every advertised order is profitable.
Ad Efficiency Inputs
Break-even ACoS equals your product gross margin (35.00%). When your ACoS stays below this line each ad-driven order is profitable. Once ACoS climbs above it, advertising costs more than the gross profit the sale generates.
ACoS (Advertising Cost of Sales) is ad spend divided by ad-attributed sales, showing how efficient a single campaign is. TACoS (Total Advertising Cost of Sales) is ad spend divided by total sales across all channels, showing how heavily your whole business leans on ads. Keep ACoS below your gross margin to stay profitable on advertised orders.
What the ACoS & TACoS Calculator Does
This calculator measures how efficiently your Amazon Sponsored Products, PPC, or paid social campaigns turn ad dollars into revenue. Enter your ad spend, ad-attributed sales, total sales, and product gross margin to instantly see your ACoS, TACoS, ROAS, and the break-even ACoS ceiling that separates profitable advertising from losing money on every click.
Who Should Use This Tool
Amazon PPC Sellers
FBA and Seller Central advertisers checking whether Sponsored Products campaigns stay under their break-even ACoS before scaling bids.
Brand & Growth Managers
Operators tracking TACoS month over month to confirm organic sales are growing faster than total ad spend.
Agencies & Freelancers
PPC managers reporting ROAS and ACoS targets to clients and setting realistic efficiency goals per product line.
DTC Paid-Media Buyers
Shopify and multichannel sellers translating Meta or Google ad results into the same ACoS and ROAS language they use on Amazon.
ACoS, TACoS & ROAS Defined
The percentage of ad-attributed revenue spent on advertising. A campaign-level efficiency metric: lower is more efficient.
Ad spend as a percentage of total sales from every channel, including organic. A whole-business health metric.
The revenue earned for every dollar of ad spend, expressed as a multiple such as 4.00x. ROAS is the inverse of ACoS.
The maximum ACoS you can run before an advertised sale loses money. It equals your product gross margin percentage.
ACoS, TACoS & ROAS Formulas
How Break-Even ACoS Works
Break-even ACoS is the point where advertising spend exactly equals the gross profit on an advertised sale. Because gross margin is the share of each sale left after product cost, it is also the largest slice you can hand back to advertising before the order stops making money. If your gross margin is 35%, your break-even ACoS is 35%. Run ads at a 25% ACoS and you keep the remaining 10 points as profit. Run them at 45% and you lose 10 points on every advertised order, even though the top-line revenue still looks healthy.
Worked Example: Amazon PPC Campaign
An Amazon brand spends $250 on Sponsored Products in a week. Those ads drive $1,000 in attributed sales, while the store rings up $3,500 in total sales across ads and organic. The product carries a 35% gross margin.
At a 25% ACoS the campaign sits comfortably under the 35% break-even ceiling, so each advertised order still earns roughly 10 points of gross profit. The 7.14% TACoS shows advertising funds only a small share of total revenue, a sign that organic sales are carrying most of the business.
ACoS vs. TACoS: Why Both Matter
ACoS answers a narrow question: how efficient is this specific campaign at converting ad clicks into sales? It is the number you optimize when adjusting bids and keywords. TACoS answers a wider question: how dependent is the whole product on paid traffic? A falling TACoS over several months means organic sales are compounding and ads are becoming a smaller part of the mix, which is exactly what a healthy Amazon launch looks like as it matures.
| Metric | Denominator | Best For |
|---|---|---|
| ACoS | Ad-attributed sales only | Campaign and keyword bid optimization |
| TACoS | Total sales, all channels | Long-term brand and organic health |
| ROAS | Ad-attributed sales only | Quick revenue-per-dollar read on ads |
Common ACoS & TACoS Errors
Frequently Asked Questions
What is a good ACoS on Amazon?
There is no universal number. A good ACoS is any figure comfortably below your break-even ACoS, which equals your product gross margin. Many sellers target 15% to 30% for established products and accept a higher ACoS during a launch when they are buying rank.
Is a higher or lower TACoS better?
A lower and gradually falling TACoS is usually healthier because it means organic sales are growing relative to ad spend. A rising TACoS can signal that the business is becoming more dependent on paid traffic to hold its revenue.
How do ROAS and ACoS relate?
ROAS and ACoS are inverses of each other. A 25% ACoS is the same as a 4.00x ROAS, and a 50% ACoS equals a 2.00x ROAS. ACoS is expressed as a percentage of sales spent on ads, while ROAS is expressed as revenue returned per ad dollar.
Why is my break-even ACoS equal to my gross margin?
Gross margin is the portion of each sale left after product cost. At break-even you spend that entire amount on advertising, so the maximum ACoS you can run before losing money is exactly your gross margin percentage.
Should I include organic sales in ACoS?
No. ACoS uses only ad-attributed sales in the denominator. If you divide ad spend by total sales including organic, you are calculating TACoS, not ACoS.
MerchSites tools and guides are written and reviewed by ecommerce practitioners. Calculations are cent-accurate estimations based on reported platform fees and standard formula math.