ACOS Calculator

ACOS is the number that tells you whether your sponsored products are making you money or quietly draining it. It's simple: ad spend divided by the sales those ads produced. Spend $500 to make $2,500 in ad-attributed sales and your ACOS is 20%. The trap is that 20% sounds fine until you remember it comes straight out of your margin.

The mistake I made early was treating ACOS like ROAS's shy cousin and never actually computing it. I'd look at "orders went up" and call the campaign a win. Then I'd check the margin and realize the ad-attributed orders were sold at a loss. ACOS fixes that blindness in one line.

What the number means

Your break-even ACOS is your profit margin before ads. If you keep 25% of the sale as margin and your ACOS is 25%, you broke even on the ad-attributed sale — you made nothing and lost nothing on those particular orders, but you paid for the privilege of the sale. Anything above your margin and you're paying out of pocket to sell.

That's the whole game with ACOS: compare it to your margin, not to some industry average someone posted in a Facebook group. A 30% ACOS is fantastic on a 60% margin product and disaster on a 12% margin one.

ACOS vs TACOS

ACOS only counts sales the ad directly caused. TACOS (total ACOS) divides ad spend by total sales, including the organic sales your ads lift. A high ACOS with a low TACOS often means your ads are pulling forward demand that would've been organic anyway — not necessarily bad, just don't read ACOS alone.

A note on margins

This calculator gives you the ACOS. To know if it's good, you need your margin. If you haven't worked that out, run the Net Profit Calculator first. The rule that keeps me safe: ACOS above your margin percent means you lose money on every ad-attributed sale. Simple as that. Turn the bid down or fix the listing before you pour more into a campaign that's red at the unit level.