Each product gets its own break-even ACOS.
An ACOS target set last year is probably out of date, because the margin under it has moved. Amazon raised FBA fees by an average of $0.08 a unit on January 15, 2026, and added a 3.5% fuel and logistics surcharge to fulfillment fees in April 2026. A new supplier price or a duty on your next shipment moves it again. So we start from what one unit keeps today, and recalculate whenever one of its costs changes.
Take the example product in our ACOS calculator. It sells for $40 and keeps $16 after a $10 product cost, a 15% referral fee of $6, a $6.50 FBA fee and $1.50 of other costs. That's 40% of the price, so its break-even ACOS is 40%. At a 30% ACOS, ads cost $12 of each $40 sale and the product keeps $4, or 10% of the price.
- A break-even and a target ACOS for every product
- Recalculated when Amazon's fees or your landed cost change
- TACOS tracked next to ACOS, to see whether total sales grow