“What is a good ACoS?” is the most-asked question in Amazon advertising and the one with the least useful common answer. Blogs will tell you 15–25%. That number is worthless on its own, because a good ACoS is entirely a function of your margin — and two sellers in the same category can have break-even points twenty points apart.
Here is how to work out your own number with Indian fees and GST, what that looks like at ₹499, ₹999 and ₹1,999, and how to set a target for each stage of a product's life. (If you are comparing ACoS with TACoS, that has its own guide: ACOS vs TACoS on Amazon.)
The three numbers, defined properly
| Metric | Formula | What it actually tells you |
|---|---|---|
| ACoS | Ad spend ÷ ad sales | Efficiency of the advertising itself |
| ROAS | Ad sales ÷ ad spend | The inverse of ACoS; same information |
| TACoS | Ad spend ÷ total sales | Whether ads are building organic strength |
| Break-even ACoS | Contribution margin ÷ price | The ceiling above which units lose money |
Step 1: Calculate your break-even ACoS
Break-even ACoS is simply how much of your selling price survives every cost except advertising. Work it out per SKU, not per account.
| Line | Amount (₹) | % of price |
|---|---|---|
| Selling price (net of GST) | 847 | 100% |
| Less: COGS | −350 | 41.3% |
| Less: Referral fee | −110 | 13.0% |
| Less: Closing + shipping | −85 | 10.0% |
| Less: Returns allowance | −45 | 5.3% |
| Contribution margin | 257 | 30.3% |
| Break-even ACoS | — | 30.3% |
Getting break-even ACoS right in India: GST and fees
Two Indian details change the number more than most sellers expect.
- Ad sales include GST. amazon.in prices are GST-inclusive, and so are the sales your campaigns report. A break-even worked out on the price net of GST must be scaled down before you compare it with reported ACoS. At 18% GST, multiply it by 0.847 (1 ÷ 1.18).
- Amazon's fees carry 18% GST. If you are GST registered you can usually claim it as input credit. If you cannot, add it to your fee line. The 0% referral fee on items under ₹1,000 in eligible categories (from March 2026) also lifts break-even on cheaper SKUs. See Amazon seller fees in India for current rates.
Break-even ACoS at common Indian price points
| Price (incl. GST) | Net of GST | COGS | Amazon fees | Returns | Contribution | Break-even (net basis) | Break-even vs reported ACoS |
|---|---|---|---|---|---|---|---|
| ₹499 | ₹423 | ₹150 | ₹95 | ₹25 | ₹153 | 36.2% | 30.6% |
| ₹999 | ₹847 | ₹350 | ₹140 | ₹45 | ₹312 | 36.8% | 31.2% |
| ₹1,999 | ₹1,694 | ₹750 | ₹406 | ₹90 | ₹448 | 26.4% | 22.4% |
The ₹1,999 product has the most rupees per unit to spend on ads but the lowest break-even percentage, because it sits above the 0% referral band. This is why one account-wide ACoS target rarely works.
What is a good ACoS? A rule of thumb by margin
| Contribution margin before ads | Break-even ACoS | Sensible mature-product target |
|---|---|---|
| 15% | 15% | 8–10% |
| 25% | 25% | 15–18% |
| 35% | 35% | 22–28% |
| 50% | 50% | 30–40% |
The target column leaves room for profit after ads. Lower it further if you need more cash from a product, or raise it towards break-even while a product is still building rank.
Step 2: Set a target ACoS by product stage
The same SKU deserves different ACoS targets at different points in its life. Treating one number as correct year-round is how sellers either starve their launches or bleed cash on mature products.
| Stage | Typical target | Objective |
|---|---|---|
| Launch (weeks 0–6) | Above break-even; capped budget | Buy review velocity and initial rank |
| Growth | At or slightly below break-even | Take share while organic builds |
| Mature / harvest | Well below break-even | Defend rank, extract profit |
| Clearance | Whatever moves stock | Avoid long-term storage charges |
Why launch ACoS is allowed to look terrible
Early ad sales do more than generate revenue — they feed the ranking signals that eventually produce free organic orders. Spending above break-even for six weeks to reach page one is an investment with a return. Spending above break-even for eight months because nobody checked the report is just a loss.
The control that matters is not the ACoS number itself but a fixed launch budget with an exit date.
Step 3: Check ACoS against total sales
ACoS only sees ad-attributed orders. Before you cut bids on a campaign that is above target, check whether total sales and organic orders are rising with it. That is what TACoS measures. Our ACOS vs TACoS guide has the formulas and a worked ₹ example, and the Amazon TACoS tracker shows TACoS per ASIN by joining Ads API spend with SP-API total sales.
Four ways sellers optimise themselves into losses
- Chasing a low ACoS by cutting bids. Impression share falls, volume falls, organic rank follows, and the ratio looks great on a shrinking business.
- Judging campaigns on a 7-day window. Amazon attribution and India's longer consideration cycles mean short lookbacks systematically understate ad performance.
- Using one ACoS target across all SKUs. A 40%-margin accessory and an 18%-margin bulk item cannot share a target.
- Ignoring the search-term report. Most wasted spend is a handful of broad-match queries that never convert. Harvest the winners into exact, negate the rest — this is the highest-ROI hour in PPC.
A practical monthly PPC routine
- Recalculate break-even ACoS per SKU — fees and COGS drift more than you expect.
- Pull the search-term report; move converting terms to exact match, negate zero-conversion spenders.
- Compare reported ACoS with the GST-inclusive break-even for each SKU, not one account-wide number.
- Re-tier every SKU into launch / growth / harvest and reset targets accordingly.
- Cross-check ad spend against settlement data so the profit line reflects reality.
ListingPilot's PPC dashboard runs this loop against live SP-API and Ads API data, and the P&L dashboard supplies the per-SKU contribution margin that break-even ACoS depends on. For the fee side of that calculation, see our breakdown of Amazon seller fees in India. To turn those targets into bid and budget rules, see Amazon PPC automation rules.