> ## Documentation Index
> Fetch the complete documentation index at: https://docs.onlinebrandgrowth.com/llms.txt
> Use this file to discover all available pages before exploring further.

# ACoS vs. TACoS: What Amazon Sellers Should Track

> The difference between ACoS and TACoS on Amazon, how to calculate each, and when each metric matters.

**ACoS (Advertising Cost of Sales) is ad spend divided by ad-attributed sales; TACoS (Total ACoS) is ad spend divided by total sales, organic included. ACoS measures campaign efficiency; TACoS measures how dependent your whole business is on ads.** Healthy accounts usually watch both - and weight TACoS more as the brand matures.

## The Formulas

* **ACoS** = ad spend ÷ ad-attributed sales × 100
* **TACoS** = ad spend ÷ total sales (organic + ad-attributed) × 100

## Why the Difference Matters

ACoS can look "bad" while the business is getting healthier: launch-phase spend that drives organic rank raises ACoS today but lowers TACoS over time as organic sales grow. Conversely, a "good" ACoS can hide an unhealthy account if ads are cannibalizing branded searches that would have converted organically anyway.

## Rules of Thumb

* **Launching a product**: expect high ACoS; watch TACoS trending down over months as organic rank builds
* **Mature product**: a rising TACoS with flat sales means growing ad dependence - investigate organic rank and conversion
* **Profit decisions**: compare each ASIN's ACoS to its **break-even ACoS** (margin before ads ÷ price) - the [Breakeven Calculator](https://www.onlinebrandgrowth.com/tools/breakeven-calculator) computes it per SKU

## The Metric Behind Both

Neither metric matters more than **contribution margin** - actual profit after all fees, ads, and COGS. That is the number OBG manages accounts to (see [Amazon PPC Management](/services/amazon-ppc-management)) and the lens of the free [OBG360 Audit](/services/obg360-audit). To see your own true margins, run the [Amazon Profit Calculator](https://www.onlinebrandgrowth.com/calculator).