The three formulas
Ad spend ÷ ad-attributed sales × 100$250 ÷ $1,000 = 25% ACOSAd-attributed sales ÷ ad spend$1,000 ÷ $250 = 4.0x ROASAd spend ÷ total sales × 100$250 ÷ $4,000 = 6.3% TACOSACOS and ROAS are the same measurement upside down: a 25% ACOS is a 4.0x ROAS, and a 50% ACOS is a 2.0x ROAS. Amazon's ad console shows ACOS; most other ad platforms show ROAS. More on ACOS.
Which sales go in which box
Ad sales are the sales Amazon attributes to a click on your ad. For sellers, Sponsored Products counts sales within 7 days of the click; Sponsored Brands and Sponsored Display count 14 days. That is why yesterday's ACOS keeps moving for a week.
Total sales are everything you sold in the same window, with or without an ad: Seller Central's Business Reports show it as ordered product sales. TACOS divides spend by this, so it shows whether ads are growing the whole business or only buying sales you would have made anyway. ACOS vs TACOS.
What to do with the number
An ACOS means nothing until you hold it against your breakeven ACOS: the share of the price you keep before ads. Under it, the campaign earns money on every sale it brings. Over it, every sale costs you. Work out your breakeven.
- ACOS under breakeven, sales flat: the campaign is profitable and may be held back by its budget or bids.
- ACOS over breakeven: find the search terms with clicks and no orders, then lower bids where the term converts too little to pay for its clicks. The weekly PPC audit.
- TACOS rising while ACOS holds: ad sales are growing faster than the business. Check whether ads are taking sales that used to come without them.
Questions
- How do you calculate ACOS on Amazon?
- Divide the ad spend by the sales Amazon attributes to those ads, then multiply by 100. $250 of spend that brought $1,000 of ad sales is a 25% ACOS.
- How do I convert ACOS to ROAS?
- ROAS is 1 divided by ACOS as a fraction. A 25% ACOS is 1 ÷ 0.25 = 4.0x ROAS.
- Why is my ACOS blank when I spent money?
- With no ad sales there is no ACOS to state: it is spend divided by zero. That is the case to act on first, because the money went out and nothing came back.