What Is a Good ACOS on Amazon? Complete Guide 2026

What Is ACOS?

ACOS stands for Advertising Cost of Sale and is the central metric for Amazon advertising. The formula is straightforward:

ACOS = Ad Spend / Ad Revenue x 100

If you spend EUR 50 on ads and generate EUR 200 in ad revenue, your ACOS is 25%. That means for every euro of ad revenue, you invested 25 cents in advertising.

A lower ACOS means you spend less on advertising to generate the same revenue. Sounds great. But here is the critical point: a low ACOS is not automatically good, and a high ACOS is not automatically bad. It depends on your goal.

An ACOS of 60% during a product launch can be strategically sound. An ACOS of 15% during a profit-maximisation phase is excellent. The number alone means nothing until you put it in the context of your margin and your strategy.

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What Is a Good ACOS?

The honest answer: it depends. A good ACOS hinges on three factors: your goal, your product margin, and your phase in the product lifecycle.

Here is a reference table:

Launch phase: You are starting a new product with zero organic ranking. Amazon only shows you if you pay for it. An ACOS of 60% means you spend EUR 60 in ads per EUR 100 revenue. That sounds steep, but you are buying sales velocity and reviews that drive organic sales later.

Growth phase: Your product already ranks organically for some keywords. Your ads complement organic ranking and push total revenue. The ACOS should gradually approach your break-even point.

Profit phase: Your product is established. You have reviews, organic ranking, and a stable conversion rate. Now you bid only on profitable keywords and maximise margin.

Remember: There is no universally good ACOS. 15% is bad if your margin is only 12%. And 40% is good if it launches your product into the top 10.

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ACOS vs TACOS vs ROAS: What Is the Difference?

Besides ACOS, there are two more metrics you should know:

TACOS (Total Advertising Cost of Sale)

TACOS = Ad Spend / Total Revenue (organic + ad) x 100

TACOS considers not just your ad revenue but your entire Amazon revenue. This matters because good advertising also boosts your organic ranking -- and therefore organic sales.

Example: You spend EUR 100 on ads. Your ad revenue is EUR 400 (ACOS = 25%). But your organic revenue is EUR 600 because your ranking improved through advertising. Your total revenue is EUR 1,000, and your TACOS is just 10%.

When to use TACOS? Whenever you want to evaluate the total effect of your advertising. A rising ACOS with a falling TACOS can mean your ads are driving more organic sales -- that is a positive sign.

ROAS (Return on Ad Spend)

ROAS = Ad Revenue / Ad Spend

ROAS is simply the inverse of ACOS. An ACOS of 25% equals a ROAS of 4 (you get EUR 4 revenue for every euro spent). Amazon itself increasingly uses ROAS in its reporting dashboards.

Which metric when? - ACOS: For daily campaign optimisation. Easy to understand, directly comparable. - TACOS: For monthly overall assessment. Shows the true ROI of your advertising. - ROAS: When working with Amazon reports or agencies. It is their standard language.

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How to Calculate Your Break-Even ACOS

Your break-even ACOS is the point where your advertising generates exactly zero profit and zero loss. It is your anchor -- anything below it is profitable, anything above it burns margin.

The formula is surprisingly simple:

Break-Even ACOS = Pre-Ad Margin (%)

Your pre-ad margin is the percentage remaining after deducting all costs before advertising. In other words:

Pre-Ad Margin = (Selling Price - COGS - Amazon Fees - Shipping) / Selling Price x 100

Worked Example

Your break-even ACOS is 36.6%. As long as your ACOS stays below 36.6%, every ad-driven sale generates profit. Above that, you lose money per sale.

In concrete terms: - ACOS 20%: You spend EUR 6.00 on ads per sale. Profit = 10.99 - 6.00 = EUR 4.99 - ACOS 36.6%: You spend EUR 10.98. Profit = EUR 0.01 (break-even) - ACOS 50%: You spend EUR 15.00. Loss = EUR -4.01

Calculate the break-even ACOS for every product in your catalogue. Without this number, you are optimising blind.

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7 Ways to Lower Your ACOS

Now it gets practical. Here are the 7 most effective levers to reduce your ACOS -- ranked by impact.

1. Maintain Negative Keywords

The fastest path to a lower ACOS: stop paying for irrelevant search terms. Go into your campaign's Search Term Report and check which search terms generate clicks but no sales.

Typical candidates for negative keywords: - Competitor brand names (if your conversion on those terms is poor) - Search terms with high clicks but zero conversions - Variants that do not match your product (wrong size, colour, pack quantity)

Maintain your negative keyword list weekly. After just 2-3 weeks, you will see your ACOS drop because you are no longer paying for worthless clicks.

2. Optimise Match Types

If you only run Broad Match campaigns, Amazon shows your ad for everything remotely related to your keyword. That gives you reach, but also many irrelevant clicks.

The approach: Broad as a research campaign, Exact as a profit campaign. Start with Broad to discover profitable keywords. Transfer winners into an Exact Match campaign and backfill the Broad campaign with negative keywords.

The workflow: 1. Broad Match runs for 2-3 weeks and collects data 2. You identify keywords with a good ACOS in the Search Term Report 3. Those keywords move into an Exact Match campaign 4. In the Broad campaign, you add them as Negative Exact to prevent double-bidding

3. Adjust Bids by Performance

Not every keyword deserves the same bid. Look at the ACOS per keyword and adjust bids accordingly:

• Keyword with ACOS below break-even: Increase bid. You are making money here -- get more of it.
• Keyword with ACOS above break-even: Decrease bid. Less spend at the same or slightly lower volume.
• Keyword with no conversions after 20+ clicks: Pause or heavily reduce.

Important: Do not change bids daily. Amazon needs 7-14 days to fully reflect changes. Adjusting bids every day means you are optimising on noise, not data.

4. Pause Unprofitable ASINs

If you run Sponsored Products on automatic targeting, Amazon shows your ad on product pages of other ASINs. In the Placement Report, you can see which ASINs drive clicks and sales -- and which only burn money.

Check regularly: Which product-targeting ASINs have an ACOS far above your break-even? Pause them. Focus your budget on ASINs that convert.

5. Improve Listing Quality

This is often overlooked: Your ACOS depends not only on your campaigns but also on your listing. A click on your ad costs money -- whether the visitor then buys is determined by your listing.

If your listing converts poorly, you pay for clicks that do not turn into sales. That pushes the ACOS up. Work on:

• Main image: Professional, clean background, clearly recognisable
• Title: Relevant keywords, easy to read, most important information first
• Bullet points: Benefits, not features. What does the customer gain?
• A+ Content: If you have Brand Registry, use it. It measurably increases conversion.
• Reviews: More and better reviews raise conversion rate

Increasing your conversion rate from 10% to 15% reduces your ACOS by one third -- with exactly the same ad spend.

6. Secure the Buy Box with Repricing

This point is so important that it gets its own section below. The short version: If you do not have the Buy Box, your ads do not convert. You pay for every click, but the customer buys from your competitor. This is the most expensive ACOS mistake there is.

A repricer ensures your price stays competitive so you hold the Buy Box. More on this next.

7. Dayparting: Focus Budget on Peak Hours

Not every hour of the day converts equally. Typically, conversion rates are higher in the evening (18:00-22:00) and on weekends than at night or early morning.

If your daily budget is limited, make sure it is not exhausted at 3 AM. Amazon now offers dayparting through its API. Alternatively, you can adjust budgets manually or use tools that pause your campaigns during low-converting hours.

By concentrating on peak hours, you reach customers who are more likely to buy -- and thereby lower your ACOS.

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The Forgotten ACOS Killer: No Buy Box

Here is the point that most ACOS guides completely ignore: You can have perfect campaigns, the best keywords, the lowest bids -- if you do not have the Buy Box, your ACOS will be terrible.

Why No Buy Box Destroys Your ACOS

Here is how it works: A customer searches for your product, sees your ad, and clicks on it. You pay for the click. The customer lands on the product page -- but the Buy Box belongs to another seller. The customer clicks "Add to Cart", and the sale goes to your competitor. You paid, they earned.

This is not an edge case. On listings with multiple sellers, the Buy Box rotates regularly. If you have 60% Buy Box share, roughly 40% of your ad clicks convert for someone else. Imagine what that does to your ACOS.

Let us do the maths: - 100 clicks at EUR 0.80 = EUR 80 ad spend - Buy Box share: 60% = only 60 clicks actually give the customer a chance to buy from you - Conversion rate: 15% = 9 sales at EUR 25 = EUR 225 revenue - ACOS = 80 / 225 = 35.6%

With 95% Buy Box share: - 95 relevant clicks, 15% conversion = 14.25 sales (rounded to 14) at EUR 25 = EUR 350 - ACOS = 80 / 350 = 22.9%

Same campaign, same keywords, same bids. But the ACOS drops from 35.6% to 22.9% -- solely because you hold the Buy Box more often.

Repricing as an ACOS Lever

A repricer solves exactly this problem. It monitors your competition in real time and adjusts your price automatically so you maximise Buy Box ownership -- without manually checking prices every day.

This is not about being the cheapest. A good repricer finds the optimal price: high enough for margin, low enough for the Buy Box. When your competitor goes out of stock, it raises your price immediately. When a new seller enters, it reacts within minutes.

The result: Your Buy Box share increases, your ads convert better, and your ACOS drops -- without changing a single keyword.

> Want to lower your ACOS right now? arbytrage.io secures your Buy Box around the clock across all EU marketplaces. Your ads convert better, your ACOS drops -- starting at EUR 40/month. Try it free

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Why Repricing and PPC Belong Together

Many sellers treat repricing and PPC as separate worlds. Price over here, advertising over there. But in reality, they are tightly connected:

• Repricing secures the Buy Box = your ads convert
• Ads drive sales = your organic ranking rises
• Organic ranking rises = you need fewer ads
• Fewer ads at the same revenue = your TACOS drops

This is a positive feedback loop. Repricing is not just a pricing tool -- it is an ACOS optimisation tool. Sellers who understand this have a real advantage over those who only tinker with their campaigns.

If you want to dive deeper into the cost savings of repricing vs. PPC, we have a dedicated article on that topic.

> Repricing + PPC = maximum profit. arbytrage.io reacts in real time to competitor price changes -- so your ad budgets do not go to waste. 6 intelligent strategies, Pan-EU support. Get started now

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FAQ

What ACOS is normal for Amazon beginners?

For beginners in the first 1-3 months, an ACOS of 30-50% is normal. Your campaigns have little data, and you have not built up negative keywords yet. Focus on collecting data and optimising your campaigns step by step rather than trying to force the ACOS down immediately.

How often should I check my ACOS?

Check your ACOS weekly at the campaign level and monthly at the account level. Daily checks lead to premature decisions -- Amazon data has up to 48 hours of delay, and individual days tell you very little. Weekly reviews give you enough data for informed optimisations.

Can my ACOS be too low?

Yes. An extremely low ACOS (below 5%) often means you are bidding too low and therefore missing impressions and sales. You only reach customers who would have bought anyway. An ACOS of 5% with 10 sales is worse than an ACOS of 20% with 100 sales -- because the total profit is higher.

Does ACOS differ across European marketplaces?

Yes, significantly. The average CPC (cost per click) varies widely: Germany and the UK are the most expensive EU markets, while Spain, Italy, and the Netherlands often have lower click prices. A Pan-EU seller can reduce their overall ACOS by shifting budgets to markets with lower CPCs. Tools like arbytrage.io support all EU marketplaces and help you secure the Buy Box on each one.

How are Buy Box and ACOS related?

Directly. If you do not have the Buy Box, your ads do not convert -- you pay for clicks, but another seller gets the sale. This drives your ACOS up massively. Based on our experience, increasing Buy Box share from 60% to 90%+ alone can reduce ACOS by 30-40%. A repricer is therefore one of the most effective ACOS optimisation tools. Read more in our Buy Box guide.

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> Is your ACOS too high? Start with the Buy Box. arbytrage.io is the repricer for EU sellers: 6 strategies, all European Amazon marketplaces, starting at EUR 40/month. Sign up free and lower your ACOS

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*Further reading:* - Amazon PPC 2026: Beginner Guide - Lower Amazon PPC Costs with Repricing - Amazon Buy Box Explained - Maximise Amazon Profit with Repricing