Convert ACOS to ROAS

ACOS and ROAS are two names for the same thing, one as a percentage and one as a multiple. Type in either value and the other follows.

How they relate

ACOS tells you what share of revenue goes into advertising. ROAS tells you how much revenue one unit of ad spend produces. Same information, read the other way round.

ROAS = 1 ÷ ACOS
ACOS = 1 ÷ ROAS

A 25 % ACOS equals a ROAS of 4.00×. A break-even ACOS of 40.8 % equals 2.45× — below that ROAS you are subsidising the sale.

Common questions

Which number is better to use?

Neither. Amazon reports ACOS, many tools report ROAS. What matters is knowing your own limit in the same unit.

What about TACOS?

TACOS relates ad spend to total revenue rather than advertised revenue. It is a different metric and cannot be converted here.

Why is a high ROAS good but a high ACOS bad?

Because they are reciprocals. A lot of revenue per unit of ad spend necessarily means a small advertising share of revenue.