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What is a good ACOS? One under your break-even.

There is no universal good ACOS. There is your break-even ACOS, set by your margin, and a target you choose under or over it.

Updated Oct 26, 2026

Free tool: Break-even ACOS calculator

Start from break-even ACOS

Your break-even ACOS is your profit margin before advertising: what is left of the price after Amazon's fees and your unit cost, as a share of the price.

Break-even ACOS(Price − referral fee − FBA fee − unit cost) ÷ price($24.99 − $3.75 − $4.50 − $6.00) ÷ $24.99 = 43%

At 43%, an ACOS of 30% keeps 13 cents of profit on every ad-driven sales dollar, and an ACOS of 50% loses 7. Get yours in a minute with the break-even ACOS calculator.

Pick a target for the job

GoalTarget ACOSWhy
ProfitWell under break-evenKeeps margin on every ad sale
Grow a proven productJust under break-evenBuys the most sales that still pay
LaunchAt or over break-even, for a set timeBuys sales history; decide the end date first
Your own brand termsFar under break-evenThese shoppers were already looking for you

Whatever the target, write it down per product. A blended account ACOS hides a product losing money behind one making plenty.

What is a good ROAS, then?

ROAS is 1 divided by ACOS, so a good ROAS is one above your break-even ROAS: 1 divided by your break-even ACOS. A 43% break-even ACOS is a 2.3x break-even ROAS; a 25% one is 4.0x. A rule of thumb like "aim for 4x" is only right for a product whose margin happens to be 25%.

Check TACOS beside it

A product can hold a good ACOS while its ads quietly take over sales it used to make without them. TACOS, ad spend over all sales, catches that: if TACOS climbs while total sales stand still, the ads are not adding anything. ACOS vs TACOS.

Questions

Is 30% a good ACOS?
It is good if your margin before ads is above 30% and a loss if it is below. Compare it with your break-even ACOS, never with another seller's number.
What is the average ACOS on Amazon?
Averages mix categories with very different margins, so they cannot tell you whether your ACOS makes money. Your break-even ACOS can.
Should my ACOS be the same on every campaign?
No. Brand campaigns usually run far lower, discovery campaigns higher. What matters is that each product's ad spend pays for itself at the target you chose.

Keep going

Get this for every product. Every week.

RankHopper reads your Amazon reports, works these numbers out for every product and keyword, and hands you the week's plan. Free during beta.