ACOS vs ROAS — Same Math, Different View

Two ways to read the same ad efficiency — percentage of revenue vs revenue multiple.

By ListCraft HQ Editorial Team

Quick answer

ACOS and ROAS describe the same relationship: ad spend vs ad-attributed revenue. ROAS = Revenue ÷ Spend (a multiple). ACOS = Spend ÷ Revenue × 100 (a %). 25% ACOS = 4x ROAS. Use ACOS on Amazon; use ROAS on Meta, Google, and most other platforms.

Side-by-side comparison

Dimension	ACOS (calculator)	ROAS (calculator)
Formula	(Ad spend ÷ Ad-attributed revenue) × 100	Ad-attributed revenue ÷ Ad spend
Unit	Percentage (e.g. 25%)	Multiple (e.g. 4x) or % (400%)
Relationship	ROAS = 100 ÷ ACOS (when ACOS is a %)	ACOS = 100 ÷ ROAS (when ROAS is a multiple)
Lower is better?	Yes — lower ACOS = more efficient	No — higher ROAS = more efficient
Primary platform	Amazon Advertising (default dashboard metric)	Google Ads, Meta, TikTok, Pinterest, etc.
Break-even at 50% margin	50% ACOS maximum	2x ROAS minimum
Mental model	"How much of each sale went to ads?"	"How many dollars of revenue per ad dollar?"
Also known as	Advertising Cost of Sale; inverse of ROAS	Return on Ad Spend; sometimes MER at business level

ACOS: Ad spend as a % of ad-attributed revenue. ROAS: Revenue as a multiple of ad spend.

When to use which

Managing Amazon Sponsored Products

Amazon Ads Center shows ACOS by campaign, ad group, and keyword. Sellers optimize bids and negatives against ACOS targets tied to product margin.

Use ACOS natively — compare to break-even ACOS (= your gross margin %). Try the ACOS calculator.

Running Meta and Google campaigns

These platforms report ROAS (or conversion value / cost). Media buyers scale ad sets with strong ROAS and cut weak ones.

Use ROAS — check against target ROAS from your margin. Convert to ACOS mentally only if you prefer percentages.

Comparing Amazon performance to Facebook

You cannot paste ACOS and ROAS into one spreadsheet column without converting. A 20% ACOS Amazon campaign equals 5x ROAS; a 5x Facebook campaign equals 20% ACOS.

Convert to one view before comparing channels — use either calculator with the same spend and revenue inputs.

Setting profitability targets from margin

At 40% gross margin, break-even is 40% ACOS or 2.5x ROAS. Many brands target below break-even (lower ACOS / higher ROAS) to leave profit after COGS.

Use break-even ACOS = margin % or break-even ROAS = 1 ÷ margin — same threshold, different notation.

Convert ACOS to ROAS (and back)

ACOS	ROAS (multiple)
10%	10x
20%	5x
25%	4x
33%	3x
50%	2x

ROAS = 100 ÷ ACOS · ACOS = 100 ÷ ROAS

Example: $2,000 spend, $10,000 revenue → ROAS = 5x → ACOS = 20%.

TACOS vs ACOS vs ROAS

ACOS / platform ROAS — ad-attributed revenue only (what the ad platform claims).
TACOS (total ACOS) — ad spend ÷ total business revenue (includes organic). Closer to blended ROAS.
Use platform ACOS/ROAS for in-channel tweaks; use TACOS or blended ROAS for business-level sanity checks.

Profitability still depends on margin

A 20% ACOS (5x ROAS) is wildly profitable at 70% margin and break-even at 20% margin. Always compare to break-even ACOS (= gross margin %) before scaling spend.

Frequently asked questions

What is the difference between ACOS and ROAS?

They are inverses of the same ratio. ACOS is ad spend divided by revenue (as a percentage). ROAS is revenue divided by ad spend (as a multiple). 25% ACOS equals 4x ROAS.

How do you convert ACOS to ROAS?

Divide 100 by ACOS percentage to get ROAS as a multiple. 20% ACOS → 100 ÷ 20 = 5x ROAS. Or divide revenue by spend directly.

How do you convert ROAS to ACOS?

Divide 100 by ROAS (as a multiple). 4x ROAS → 100 ÷ 4 = 25% ACOS. Or compute (spend ÷ revenue) × 100.

Which does Amazon use, ACOS or ROAS?

Amazon Advertising uses ACOS by default in campaign reporting. Some sellers mentally convert to ROAS, but the platform UI and seller forums speak in ACOS.

Is lower ACOS always better?

Lower ACOS (higher ROAS) is better for efficiency, but extremely low ACOS can mean under-bidding and lost sales. Target profitable ACOS below your gross margin, not necessarily the lowest possible.

What is a good ACOS or ROAS?

Break-even ACOS equals your gross margin (e.g. 50% margin → 50% ACOS max = 2x ROAS min). "Good" means below that threshold with room for profit — often cited 15–25% ACOS (4–6.7x ROAS) for ecommerce, but margin decides.