Break-Even ACoS Calculator for Amazon India Sellers (2026)
Published 15 May 2026 · 6 min read · Indian Amazon Seller Playbook
Every Amazon ads dashboard talks about ACoS — but the number Amazon shows you is meaningless without one thing: your Break-Even ACoS. That's the ceiling above which every additional ad rupee burns profit. This post gives you the right formula for Indian sellers — one that doesn't lie about GST, FBA fees, and returns.
TL;DR: Most "ACOS calculators" use gross revenue and a flat referral fee. Indian sellers face GST, FBA fees, weight handling, return rates, and storage charges. Calculate your net margin per unit first, then back into Break-Even ACoS.
1. What Is Break-Even ACoS?
Break-Even ACoS is the percentage of a sale you can spend on advertising before profit hits zero. Spend below it = profitable ad. Spend above it = ad-funded loss.
Break-Even ACoS = (Net Margin per Unit / Selling Price) × 100
where Net Margin = Selling Price − COGS − Amazon Fees − FBA Fees − GST Outflow − Returns Provision − Storage
"Net Margin" here is the rupees that hit your bank account per unit sold, after every Amazon-side deduction and before tax filing. It is not the gross profit Seller Central shows.
2. The India-Specific Formula
For Indian Amazon sellers, the proper unit-level computation looks like this:
Net Margin = Sale Price
− Cost of Goods (COGS)
− Referral Fee (typically 4–15 % by category)
− Closing Fee
− Weight Handling Fee (FBA / Easy Ship)
− Pick & Pack Fee (FBA only)
− Storage Fee per Unit (monthly storage ÷ velocity)
− Return Loss Provision (Return Rate × per-return cost)
− Net GST Outflow (output GST − input GST credit)
Then:
Break-Even ACoS = (Net Margin ÷ Sale Price) × 100
3. Worked Example
SKU: a stainless-steel water bottle on Amazon India, FBA.
| Line | ₹ per unit |
|---|
| Selling price (incl. GST) | 499 |
| − Output GST (18 %) | −76 |
| = Pre-tax selling price | 423 |
| − COGS (incl. input GST credit applied) | −140 |
| − Referral fee @ 13 % of MRP | −65 |
| − Closing fee | −10 |
| − FBA weight handling + pick & pack | −60 |
| − Storage per unit (allocated) | −4 |
| − Return provision (8 % × ₹35) | −3 |
| Net margin per unit | ₹141 |
Break-Even ACoS = 141 ÷ 499 = 28.3 %.
That means: any advertising spend above 28.3 % of the sale price is burning profit. Most Amazon India sellers run blind at 35 – 50 % ACoS and wonder why they grow revenue but not cash.
4. Target ACoS — The Profit Layer
Break-Even ACoS is the ceiling. Your Target ACoS is what you actually aim for in campaigns:
Target ACoS = Break-Even ACoS × (1 − desired profit margin %)
If you want 20 % cash margin on advertised sales, target ACoS for the example SKU = 28.3 % × (1 − 0.20) = 22.6 %.
5. Why Most Calculators Are Wrong for India
- They ignore GST netting. Output GST on the sale isn't yours to keep; input GST credit on inputs offsets only part of it. Treat the net GST outflow as a real cost.
- They use category-average fees. Amazon's fee schedule is SKU-specific (weight, dimensions). One bulky SKU can have a totally different break-even than another in the same category.
- They skip returns. India return rates run 5 – 20 % depending on category. Apparel and shoes can be brutal. Return logistics costs ₹30 – 70 per returned unit.
- They skip storage. Storage per unit depends on velocity. A SKU that sits 6 months and a SKU that sits 3 weeks have wildly different effective COGS.
6. Where SLM Computes This For You
SLM ingests your Amazon Seller Central reports and computes per-SKU:
- Contribution Margin (CM) after every Amazon-side fee
- Net Take-Home in rupees
- Break-Even ACoS, automatically per SKU
- Whether your current ad spend is above or below that ceiling — flagged as a Risk action
No bidding blind. No averaging. Every SKU gets its own number.
7. Frequently Asked
What is Break-Even ACoS?
The ad-spend percentage at which profit is zero. Below it, ads are profitable; above it, they burn margin.
Is Target ACoS the same?
No. Target ACoS is the spend ceiling that hits your desired margin. Target = Break-Even × (1 − desired margin %).
How do GST and returns affect ACoS in India?
Both reduce the rupees available per sale for ads. Skip them in the calc and you'll set targets that look healthy but quietly destroy cash.
Stop guessing ACoS — let SLM calculate it per SKU →