ACoS Calculator: Find Your ACoS, ROAS and Break-Even ACoS in Rupees

ACoS (advertising cost of sales) is your ad spend divided by the sales those ads brought in, multiplied by 100. Spend ₹5,000 to earn ₹25,000 in ad sales and your ACoS is 20%. The number that matters is your break-even ACoS. Amazon's guide says ACoS must be lower than your profit margin, or ad spend exceeds earnings. Use the calculator below with your own figures, as of November 2026.

What the calculator uses

There are no market rates built in. Every default is a placeholder for an imaginary product priced at ₹799 (excluding GST), so you must replace them with your own numbers. The two formulas come from Amazon Ads: ACoS = (ad spend ÷ ad revenue) × 100, and ROAS = ad revenue ÷ ad spend. The break-even step is our reading of Amazon's rule that ACoS should stay under profit margin. Amazon's guide does not print a break-even formula, so treat this step as our working, not an Amazon statement.

ACoS and break-even ACoS calculator

How the formula works, with a worked example

For example, a kitchen organiser sells at ₹799 excluding GST. Product cost is ₹300, marketplace fees ₹120, and shipping, packaging and a return allowance come to ₹60. Profit before ads is ₹799 − ₹300 − ₹120 − ₹60 = ₹319 per unit. That is 39.9% of the price, so the break-even ACoS is about 39.9%.

Now the ads. You spend ₹5,000 and the ads bring ₹25,000 in sales. ACoS is 5,000 ÷ 25,000 × 100 = 20%. ROAS is 25,000 ÷ 5,000 = 5. Break-even ROAS is 100 ÷ 39.9, about 2.5, so you are well inside profit. Those ad-sold units are about 31, giving roughly ₹9,980 before ads and ₹4,980 after the ₹5,000 spend.

Amazon's own illustration of the formula uses $50 of spend and $100 of sales for a 50% ACoS and a ROAS of 2.

Why your margin sets the limit

Amazon recommends first reaching your break-even ACoS and comparing it to your profit margin when you set a target. The same guide gives no universal "good" ACoS, because it varies by industry, company size and campaign frequency. A 40% break-even product and a 12% break-even product need different targets. Copying a number from a blog is how sellers overspend.

Fees matter too. Since 16 March 2026, Amazon.in charges zero referral fee on products under ₹1,000 across 1,800+ categories. Amazon's seller guide also lists lower Self-Ship closing fees: ₹20 for products under ₹300 and ₹26 for ₹300 to ₹500. Lower fees raise your margin and so your break-even ACoS. Recheck your numbers if a SKU moved into that band. Our Amazon seller fee calculator helps with the fee line.

Amazon's marketing ROI guide defines gross profit as total revenue minus cost of goods sold, and says to count all relevant costs, not only ad spend. Its advertising budget guide also says there is no universal formula for a good ad budget.

What the calculator does not cover

• It only counts sales the ads were credited with. Organic sales lifted by ads are not included; see ACoS vs TACoS vs ROAS for the total-sales view.
• It treats product cost, fees and extras as fixed per unit. Returns, RTO and discounts change real margin.
• Break-even ACoS means zero profit on ad-sold units. Launch campaigns may run above it on purpose; that is a decision, not a target.
• It does not know your platform. The maths is the same on Amazon.in and Flipkart, but Flipkart reports ad metrics in its own way, so check how your dashboard defines "revenue".

FAQ

What is a good ACoS in India? There is no single good ACoS. Amazon's guide says it depends on your industry, company size and campaign frequency. A good ACoS for you is one below your break-even ACoS and at or below the profit you want per unit. Work it out per product, not per account.

How do I calculate break-even ACoS? Divide profit per unit before ads by selling price, then multiply by 100. For a ₹799 product with ₹319 profit before ads, that is 39.9%. Amazon says ACoS must be lower than profit margin to stay profitable. The calculator above does this for you.

What is the difference between ACoS and ROAS? They use the same two numbers. ACoS is ad spend over ad revenue as a percentage. ROAS is ad revenue over ad spend. A 20% ACoS equals a ROAS of 5. Lower ACoS is better, higher ROAS is better. See the ROAS glossary entry.

Should I include GST in the price? Use price excluding GST, and fees excluding GST, so both sides are on the same basis. GST you collect is not your revenue. Ad sales reported by a dashboard may include or exclude tax, so check how yours defines revenue before comparing.

Can I run ads above break-even ACoS? Sometimes, on purpose: a new launch, a review push, or a product with strong repeat purchase. You are then paying for something other than this order's profit. Set a limit on how long and how much, and review it weekly. Do not let it become the default for a whole account.

Does a lower ACoS always mean better ads? No. A very low ACoS can mean you are only bidding on terms you already win and missing growth. Check total sales too, with TACoS. The aim is the most profit, not the smallest percentage.

Get ACoS targets set per SKU

If you want targets set from real margins across a whole catalogue, Blooprint's team can run that on Amazon.in and Flipkart through catalogue and listing optimisation, alongside ads. BlooprintAI (blooprintai.in) is the ads-automation software we build.