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Amazon PPC & ACoS Calculator

On Amazon, a low ACoS can still lose money and a high one can still win. Enter your price, cost and fees to find your break-even ACoS, your true profit per unit, and the target ACoS your margins can actually support.

By the Digital Success paid-media team · Updated September 2026 · Free, results in seconds

The short version: ACoS (ad cost as a percent of ad sales) only means something next to your break-even ACoS, the point where ad cost equals your profit margin. This calculator works out your break-even ACoS from price, cost and Amazon fees, your profit per unit, your TACoS if you add total sales, and the target ACoS and max bid that keep each sale profitable.
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Find your break-even ACoS and profit

Enter your product economics. Price, cost and fees give you break-even ACoS; add spend and sales for your actual ACoS. All in your browser.

What you get

The one number Amazon sellers most often miss: your break-even ACoS, the point where advertising cost eats exactly your profit margin. From your price, cost and Amazon fees the calculator works it out, along with your true profit per unit, and when you add ad spend and sales it shows your actual ACoS against that break-even, and whether each ad-driven sale is making or losing money. Add total sales and it shows TACoS too. Then it gives you a target ACoS that keeps a healthy margin and the room you have to bid for more volume.

How it works

  1. Enter your selling price, product cost and Amazon fees (referral plus FBA).
  2. Add ad spend and ad sales to get your actual ACoS, and total sales for TACoS.
  3. See your break-even ACoS, profit per unit and whether you are winning.
  4. Open the full breakdown and the target ACoS your margins support.

Why ACoS alone is a trap

Sellers celebrate a low ACoS and panic at a high one, but both reactions can be wrong. A 15% ACoS looks great until you realize your margins only supported a 40% break-even and you were leaving profitable volume, and rank, on the table by bidding too timidly. A 40% ACoS looks alarming until you realize your break-even was 50% and every one of those sales was profitable while also lifting your organic rank. The only way to know is to compare your ACoS to your break-even ACoS, and to watch TACoS over time to confirm your ads are building the business, not just renting sales. This calculator gives you both, so you can bid with confidence instead of superstition.

Frequently asked questions

What is ACoS?
Advertising Cost of Sale: ad spend divided by ad-driven sales, as a percentage. On its own it says nothing about profit, that depends on your break-even ACoS.
What is a good ACoS?
Any ACoS below your break-even ACoS, which is your margin before ad spend. This tool calculates your specific break-even point.
ACoS vs TACoS?
ACoS measures ad spend against ad-attributed sales; TACoS measures it against total sales including organic. Falling TACoS over time is a healthy sign ads are lifting organic rank.
What is break-even ACoS?
The ACoS where ad cost equals your margin, so the ad sale makes zero profit. It is your profit margin after product cost and Amazon fees, the most important number in Amazon PPC.
Should I always aim for the lowest ACoS?
No. A very low ACoS can mean under-investing and missing profitable sales and rank. Aim for the most volume you can drive under break-even, or a deliberate temporary higher ACoS to win rank on a new product.
Is it free?
Yes, free with no login, calculated in your browser. Share your details once to open the full breakdown and targets.

Further reading from Digital Success

Want your Amazon ads run to profit, not just ACoS?

Hitting a target ACoS while scaling takes constant bid, keyword and negative work. Digital Success manages Amazon and retail-media campaigns to profit. Talk to a specialist for a free review.

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