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In short
- ACoS = ad spend ÷ ad sales × 100. It measures how efficiently your ads turn spend into sales.
- It only counts sales credited to ads, so it says nothing about organic sales. TACoS covers those.
- A good ACoS is one below your break-even ACoS, which equals your margin before ad costs.
- Lower is not always better: a very low ACoS can mean you are missing sales you could afford to buy.
Why ACoS matters
ACoS is the quickest way to see whether your ad spend is paying for itself. Because it is a ratio, you can compare a $50 campaign with a $50,000 one, or one keyword with another, on the same scale.
- It shows profit or loss per ad sale. Put ACoS next to your margin and you know straight away whether each ad-driven sale makes or loses money.
- It points to waste. A keyword or product with an ACoS far above the rest of the account is usually where the wasted spend is.
- It guides bids. Most bid changes, by hand or by rule, aim to move ACoS toward a target.
- It is the number Amazon shows first. ACOS sits in the main columns of Campaign Manager, so it is the metric most teams talk about.
Who uses ACoS
Everyone who touches Amazon advertising reads ACoS, but each role reads it for something different.
| Who | What they use ACoS for | How often |
|---|---|---|
| PPC manager or agency | Raising and cutting bids, adding negatives, judging keywords and campaigns | Weekly, per keyword |
| Brand owner or founder | Checking that advertising pays for itself and setting targets per product | Monthly |
| Finance team | Folding ad cost into product profit and budgets | Monthly or quarterly |
| Product or launch manager | Setting a time-limited ACoS above break-even to build rank for a new product | Weekly during a launch |
How ACoS works
ACoS links two numbers Amazon tracks for every campaign: what you paid for clicks and what those clicks sold.
- 01A shopper clicks your ad
You pay the cost per click set by the auction. That cost adds to ad spend.
- 02The shopper buys within the attribution window
Sponsored Products credits sales made within 7 days of a click for sellers (14 days for vendors); Sponsored Brands and Sponsored Display use 14 days.
- 03Amazon credits the sale to the ad
The order value is added to ad sales for that campaign, ad group, keyword and product.
- 04ACoS is worked out
Ad spend divided by ad sales, times 100, for whatever level and date range you are looking at.
Because sales keep arriving for up to 14 days after a click, ACoS for the last week or two looks higher than it will end up. Judge it on a closed date range.
Where you find ACoS on Amazon
| Where | What you see | Good for |
|---|---|---|
| Amazon Ads console, Campaign Manager | ACOS column for campaigns, ad groups, keywords and targets | Day-to-day checks and bid changes |
| Amazon Ads reports | Spend and sales by search term, target, placement and product | Finding wasted spend and new keywords |
| Bulk operations files | Spend and sales per keyword and target in a spreadsheet | Changing many bids at once |
| Seller Central | No ACoS; Business Reports show total sales | Working out TACoS alongside ACoS |
ACoS formula and example
The formula is the same at every level, from one keyword to the whole account.
ACoS = Ad spend ÷ Ad sales × 100ACoS = 100 ÷ ROAS| Item | Value | How |
|---|---|---|
| Ad spend | $1,200 | From Campaign Manager, last 30 days |
| Ad sales | $4,000 | Same campaigns, same dates |
| ACoS | 30% | 1,200 ÷ 4,000 × 100 |
| ROAS | 3.33 | 4,000 ÷ 1,200 |
| Margin before ads | 32% | Price $40, costs before ads $27.20 |
| Verdict | Small profit | 30% ACoS is 2 points under the 32% break-even |
What is a good ACoS?
There is no good ACoS in general, only a good ACoS for a given margin and goal. The same 30% ACoS loses money on a product with a 25% margin and makes money on one with a 40% margin. Compare ACoS with your break-even ACoS, then decide what the product needs.
| Situation | ACoS against break-even | What it means | Next move |
|---|---|---|---|
| Room to grow | Well below | Ad sales are very profitable, and you may be missing sales | Raise bids on searches that sell; add new keywords |
| On target | Below, near your target | Ads make the profit you planned | Hold; keep cutting waste |
| Investing for rank | Above, on purpose | Ad sales lose money to build organic rank | Set an end date and a target, then step bids down |
| Losing money | Above, with no plan | Every ad sale costs you money | Add negatives, lower bids, fix the listing |
Set a target ACoS per product: break-even ACoS minus the profit you want to keep.
ACoS vs TACoS, ROAS and break-even ACoS
| Metric | Formula | Counts organic sales? | Answers |
|---|---|---|---|
| ACoS | Ad spend ÷ Ad sales × 100 | No | How efficient are my ads? |
| TACoS | Ad spend ÷ Total sales × 100 | Yes | What do ads cost against the whole business? |
| ROAS | Ad sales ÷ Ad spend | No | How much comes back per $1? (100 ÷ ACoS) |
| Break-even ACoS | Margin before ad costs | n/a | What is the most ACoS I can afford? |
How to lower ACoS without losing sales
Cutting every bid lowers ACoS, and usually sales with it. These moves remove waste instead.
Common ACoS mistakes
- Judging the last few days. Sales are still being credited for up to 14 days, so recent ACoS looks worse than it is.
- One target for the whole account. Margins differ by product, so break-even ACoS does too.
- Chasing the lowest ACoS. A very low ACoS often means bids are too low to win the searches that would sell profitably.
- Ignoring TACoS. Pausing a high-ACoS campaign can cut total sales by more than it saves, if those ads were holding organic rank.
- Comparing across categories. A 40% ACoS can be fine for a high-margin product and a disaster for a low-margin one.
Authoritative resources
Frequently asked questions
What does ACoS stand for?
How do you calculate ACoS?
What is a good ACoS on Amazon?
Is a lower ACoS always better?
What is the difference between ACoS and TACoS?
Why is my ACoS so high?
Where can I see ACoS in Amazon?
Last updated Oct 3, 2026 by the Amplivus strategy team. Part of the Amazon PPC glossary.