Break-even ACoS on Amazon India: how to set your target
Break-even ACoS is the ad cost of sales at which an Amazon sale makes exactly ₹0 profit. Work it out as your profit per unit before ads, divided by the selling price. If your ACoS runs above that number, every ad-driven order loses money. Many Indian sellers set a "25% ACoS" target because it sounds sensible, without ever checking it against their margin. Here is how to work out the real number for your product and turn it into bids.
ACoS, ROAS and the break-even line
Amazon Ads defines ACoS as ad spend divided by ad-attributed sales, multiplied by 100. ROAS is the same ratio flipped: ad sales divided by ad spend. A 25% ACoS equals a 4.0 ROAS, and a 50% ACoS equals a 2.0 ROAS.
Amazon's guidance is clear on one point: your ACoS has to stay below your profit margin, or the ads cost more than they earn. Its guide also notes that ACoS "shouldn't be the sole campaign metric you focus on". We come back to that below.
How to calculate break-even ACoS
Use this formula:
Break-even ACoS = (Selling price − GST − Amazon fees − product cost − other variable costs) ÷ Selling price
Here is a worked example built on Amazon's own numbers. In its March 2026 fee announcement, Amazon showed a pair of earphones priced at ₹798 and fulfilled by Amazon. Total fees came to ₹109 after referral fees were removed for products under ₹1,000. The cost lines below are our assumptions, there for illustration.
| Line | ₹ per unit |
|---|---|
| Selling price (incl. 18% GST) | 798 |
| Less GST (798 − 798/1.18) | −122 |
| Less Amazon fees (Amazon's example) | −109 |
| Less landed product cost (assumed) | −300 |
| Less returns and damage allowance (assumed) | −25 |
| Profit before ads | 242 |
| Break-even ACoS | 242 ÷ 798 = 30.3% |
The denominator is the full selling price because Amazon reports ad sales at the price the customer paid. If you divide by the net-of-GST price instead, you'll overstate how much room you have.
On fees: GST charged on marketplace fees can usually be claimed as input credit by a registered seller, so we've left it out here. Check the treatment with your CA.
From break-even to target ACoS
Break-even ACoS is a ceiling, not a target. Set the target by what that product needs to do for you:
| Goal for the product | Target ACoS | In this example |
|---|---|---|
| Profit now (mature, ranked SKU) | Break-even minus desired margin | 30% − 12% = 18% |
| Hold rank in a competitive category | Close to break-even | 25–28% |
| Launch or rank push (time-boxed) | Above break-even, on purpose | 35–45% for 4–6 weeks |
The launch row is where sellers lose the most money. Spending above break-even is a deliberate investment in reviews and organic rank, so give it an end date and a budget cap, for example ₹40,000 over six weeks. Don't let it become the permanent state of the campaign.
Turn it into a maximum bid
ACoS is an outcome, but you control bids. To link the two:
Max CPC = Average order value × Conversion rate × Target ACoS
For the earphones, take an average order value of ₹798, a 10% conversion rate from the Search term report, and an 18% target. That gives a maximum CPC of about ₹14. At break-even (30.3%), the ceiling is about ₹24. If the keywords you want cost ₹30 a click, the maths tells you to fix conversion (images, price, reviews) or the margin before raising bids.
Do this per keyword cluster, not per account. Branded terms often convert at 20%+ and can take higher bids. Broad generic terms like "wireless earphones" may convert at 5% and need much lower bids.
Why ACoS alone misleads
Two things to keep in mind:
- Ads drive organic sales too. A product ranked through ads sells more without any ad click. Track TACoS, which is ad spend divided by total sales including organic. If ACoS stays flat while TACoS falls, your ads are building rank.
- Low ACoS can mean under-investment. A 10% ACoS on a hero SKU with 30% break-even may mean you are missing volume. Check impression share and the top-of-search placement report before cutting bids further.
This is the same trap as judging Google or Meta by ROAS alone, which we covered in our Performance Max insights post and our guide to the Meta Ads metrics that matter.
Where Indian sellers get the maths wrong
- Leaving out GST. On an 18% GST product this alone inflates the margin by about 15 percentage points.
- Ignoring returns and RTO. In categories like fashion, returns can wipe out the margin on a large share of orders. Use your own return rate, not a guess.
- Using old fee numbers. Amazon India changed referral fees for many sub-₹1,000 products from 16 March 2026. Re-run your break-even with the current fee schedule for each price band.
- One target for the whole account. A ₹299 T-shirt and a ₹2,499 trimmer can't share an ACoS target.
What to do this week
- Build a sheet with one row per top-20 SKU: price, GST rate, current Amazon fees, landed cost, return allowance.
- Calculate break-even ACoS for each and mark any campaign running above it without a launch reason.
- Set a target ACoS per SKU using the goal table above.
- Work out the max CPC for your top 10 keywords from the real conversion rates in your Search term report.
- Add TACoS to your weekly report alongside ACoS.
- Give every launch campaign an end date and a ₹ budget cap.
FAQ
What is a good ACoS on Amazon India?
There is no universal good number. A good ACoS sits below your break-even ACoS by the margin you want to keep. For one product that may be 15%, and for another it may be 35%.
Is break-even ACoS the same as profit margin?
It's your profit margin before advertising, expressed as a share of the selling price. Spend exactly that percentage on ads and you make ₹0 on the sale.
Should I include FBA storage fees?
Yes, if they're material. Spread monthly storage across the units you sell that month and add it to "other variable costs". This matters most for slow-moving or bulky items.