ACOS, ROAS and TACoS: which number should you actually manage to?

Open any marketplace ads dashboard and you will meet the same three acronyms. They are easy to mix up, and managing to the wrong one is one of the most common reasons good accounts drift.

1ROAS: how many rupees of sales per rupee of ads

Return on ad spend is ad-attributed sales divided by ad spend. A ROAS of 4.0x means every ₹1 spent is credited with ₹4 of sales. It is the number most people quote because bigger feels better.

2ACOS: the same ratio, upside down

Advertising cost of sales is ad spend divided by ad-attributed sales, shown as a percentage. It is simply the inverse of ROAS: a 25% ACOS is a 4.0x ROAS. Neither is more correct. Pick one and use it consistently so the team is not translating in meetings.

3TACoS: ads against the whole business

Total advertising cost of sales is ad spend divided by total sales, organic included. ROAS and ACOS only look at sales the ad gets credit for. TACoS asks a bigger question: as I spend on ads, is the whole account getting healthier?

If TACoS falls while sales grow, ads are helping products rank and convert organically. If TACoS climbs while total sales stay flat, you are mostly paying for sales that would have come anyway.

4Set the target from margin, not from a benchmark

Your break-even ACOS is the share of the selling price left after product cost, marketplace fees, shipping and returns, before ads. A simple illustration:

• Selling price ₹1,000. After cost, fees and shipping you keep ₹300.
• Break-even ACOS is 30%. Break-even ROAS is 1 ÷ 0.30, about 3.3x.
• Spending to a 30% ACOS means the ad sale makes no profit, but it may still be worth it for a new product that needs rank and reviews.

The right target is usually different by product and by goal. A mature bestseller should run well below break-even. A launch can run above it for a defined period.

5A practical way to use all three

1. Use ACOS or ROAS to judge individual campaigns and keywords.
2. Use TACoS to judge the account and the overall budget.
3. Review all three together weekly, and write down what you changed because of them.

If you would like these numbers read against your own account, that is exactly what the free audit does.