ACoS = ad spend as % of ad revenue. TACoS = ad spend as % of total business revenue (organic + paid). ROAS = revenue per rupee of ad spend. Monitor all three. A falling TACoS over time — even as revenue grows — means your ads are working exactly as they should: building free organic rank.
EcomSarthi Editorial Team··12 min read
Amazon ACoS vs TACoS vs ROAS — What Each Metric Means and What to Target in India
When I started managing Amazon accounts, sellers used to ask me "is my ACoS good?" — and the honest answer is: ACoS alone doesn't tell the full story. You need all three metrics to understand if your advertising is actually building a healthy business. Here's everything you need to know, with real Indian seller examples.
1. What is ACoS? — Formula, Meaning & Real Examples
ACoS (Advertising Cost of Sale) answers a simple question: for every ₹100 of revenue that came from ads, how much did I spend? It measures the efficiency of your advertising against ad-attributed sales only.
# ACoS Formula
ACoS = (Ad Spend ÷ Ad Revenue) × 100
# Real example:
Ad Spend this week = ₹8,000
Ad-attributed Revenue = ₹40,000
ACoS = (8,000 ÷ 40,000) × 100 = 20%
# Meaning: for every ₹100 of ad sales, you spent ₹20 on ads
Lower ACoS = more efficient ads relative to ad sales. But there's a critical nuance that trips up many Indian sellers: a "good" ACoS depends entirely on your product margin. If your gross margin is only 18%, even a 12% ACoS might leave you with zero profit after all costs.
ACoS Range
Signal
When Acceptable
Under 15%
Very efficient
Mature ranked product, brand defence keywords, or hero SKUs with strong CVR
15–25%
Healthy
Well-optimised growing accounts with 35%+ net margins
25–35%
Moderate
Acceptable for growth phase; review keyword-level waste
35–50%
High
Only for new launches or products with 50%+ margins
Above 50%
Loss territory for most
New launch rank-building with clear organic upside — not ongoing
2. What is TACoS? — The Metric That Actually Tells You If Your Ads Are Working
TACoS (Total Advertising Cost of Sale) is the metric most Indian sellers haven't heard of — but should be tracking above all others. The difference from ACoS is what it divides by: instead of ad revenue, TACoS uses your total revenue — organic + paid.
# ACoS sees 1/5 of the picture. TACoS sees the full business.
Why TACoS Trend Matters More Than the Number
A falling TACoS over 6 months — while revenue grows — is the single best signal that your advertising is working correctly. It means organic traffic is rising faster than ad spend, because ads built your ranking. Organic traffic is free. If your TACoS was 20% six months ago and is 9% today, your strategy is working perfectly. Most sellers obsess over ACoS and miss this bigger picture.
3. What is ROAS? — The Inverse of ACoS
ROAS (Return on Ad Spend) expresses the same information as ACoS but as a multiple instead of a percentage. "I earned ₹5 for every ₹1 spent on ads" is easier to say than "20% ACoS" — which is why agencies and client reports often use ROAS.
# ROAS Formula
ROAS = Ad Revenue ÷ Ad Spend
# ACoS ↔ ROAS conversion:
ROAS 5 = ACoS 20% (1 ÷ 5 = 0.20)
ROAS 4 = ACoS 25% (1 ÷ 4 = 0.25)
ROAS 3 = ACoS 33% (1 ÷ 3 = 0.33)
Target ROAS = 1 ÷ Target ACoS (decimal)
Track all three metrics weekly. A simple 5-column spreadsheet: week, ad spend, ad revenue, total revenue, compute ACoS/TACoS/ROAS — 10 minutes setup, months of insight.
EcomSarthi pulls your actual advertising data, benchmarks it against your product margins, and shows you exactly where spend is wasted. Free audit, no commitment.
ACoS (Advertising Cost of Sale) = (Ad Spend ÷ Ad Revenue) × 100. If you spend ₹1,000 on ads and earn ₹5,000 in ad-attributed sales, your ACoS is 20%. It measures how efficiently your ad spend generates ad-attributed revenue — but not your total business health.
What is TACoS and why does it matter more?
TACoS = (Ad Spend ÷ Total Revenue) × 100. It measures ad spend as a share of your entire business revenue — organic and paid. A falling TACoS over time is the single best signal that your advertising is building organic rank, reducing your dependence on paid ads while growing revenue.
What is a good TACoS for Amazon India?
A healthy TACoS for a growing Amazon India business is 8–15%. New launches may have TACoS of 20–30%. Mature products with strong organic rank should target below 10%. Track the trend — a consistently falling TACoS is more important than any specific number.
What is ROAS on Amazon?
ROAS = Ad Revenue ÷ Ad Spend. ROAS of 5 means every ₹1 of ads generated ₹5 in ad revenue. It is mathematically the inverse of ACoS (ROAS of 5 = ACoS of 20%). Target ROAS = 1 ÷ Target ACoS (as a decimal).
Is a high ACoS always bad?
Not always. For new product launches, accepting ACoS at or above break-even is intentional — you are investing in organic rank that will drive free revenue later. The test is whether TACoS falls over the next 90–180 days as organic sales grow. If yes, the high launch ACoS was worth it.
What's more important — ACoS or TACoS for decision making?
Use ACoS for daily/weekly campaign optimisation (bid adjustments, negative keywords). Use TACoS for monthly business health assessment. Both matter, but TACoS shows whether your advertising is building long-term organic business — which ACoS cannot.
EcomSarthi Editorial Team·
·12 min read
