Amazon PPC ROAS Calculator

ROAS on Amazon Ads

Amazon advertisers usually talk in ACoS (ad cost of sales = spend ÷ sales), which is simply 1 ÷ ROAS: a 4.0× ROAS is a 25% ACoS. This calculator gives you ROAS; divide 100 by it for ACoS. The break-even figure matters more on Amazon than anywhere else because the margin you enter must already be net of referral fees, FBA fees and returns — a 30% margin after fees means break-even ROAS of 3.33× (ACoS 30%).

Amazon's attribution window is 7 days for Sponsored Products and 14 days for Sponsored Brands, and it includes sales of other ASINs in your catalogue after an ad click. Ranking campaigns for a new listing are often run below break-even on purpose to earn organic rank; that is a deliberate investment, and this calculator tells you exactly how much you are paying for it per period.

Formula

ROAS = Revenue from ads ÷ Ad spend
Break-even ROAS = 1 ÷ Gross margin
Profit after ad spend = (Revenue × Gross margin) − Ad spend

How to read ROAS

ROAS answers one question: for every unit spent on ads, how much revenue came back? A ROAS of 4.0 (or 400%) means each 1 spent returned 4 in revenue. It says nothing about profit, which is why the break-even figure matters more than the headline number.

Break-even ROAS is the inverse of gross margin. At a 40% margin you need a 2.5× ROAS just to cover the cost of goods and the ads; anything below that loses money on every sale even though revenue is growing. Set campaign targets above break-even, not above zero.

Frequently asked questions

How do I convert ROAS to ACoS?

ACoS = 100 ÷ ROAS. A 5× ROAS is a 20% ACoS; a 2× ROAS is a 50% ACoS. Break-even ACoS equals your margin after Amazon fees, which is the same statement as break-even ROAS = 1 ÷ margin.

Should I include TACoS?

TACoS (total ad cost of sales = ad spend ÷ total sales including organic) is the metric to watch over months: falling TACoS with steady ad spend means ads are lifting organic rank. This calculator is per-campaign ROAS; compute TACoS separately from your total sales report.

What is a good ROAS?

A ROAS comfortably above your break-even ROAS. For a 50% margin business break-even is 2.0×, so 3–4× leaves room for profit; for a 20% margin business break-even is already 5.0×. The same ROAS number can be excellent for one business and a loss for another.

Why is my ROAS different in Google Ads, Meta and GA4?

Each platform attributes conversions with its own window and model, and platform-reported ROAS usually double-counts across channels. Use platform ROAS to optimise within a channel and a blended figure (total revenue ÷ total spend) to judge the overall budget.

Should ROAS include ad spend in the margin?

No. Gross margin here is revenue minus cost of goods and fulfilment, before advertising. Ad spend is the denominator of ROAS, so including it in the margin would count it twice.

How does break-even ROAS change with returns and refunds?

Refunds reduce effective gross margin. If 8% of orders are refunded, multiply your margin by 0.92 before inverting it, and the break-even ROAS rises accordingly.