ACOS to ROAS Converter
Reciprocals, converted either way.
ROAS
3.57×
from 28% ACOS
They are reciprocals: ROAS is 100 divided by ACOS, and ACOS is 100 divided by ROAS. A 25% ACOS is a 4× ROAS. Amazon reports ACOS, Meta and Google report ROAS, and teams comparing the two across platforms regularly compare them incorrectly.
How the ACOS to ROAS Converter works
ACOS and ROAS are reciprocals: a 25% ACOS is a 4× ROAS, and a 2× ROAS is a 50% ACOS. Amazon reports one, Meta and Google report the other, and teams comparing performance across platforms regularly compare them incorrectly.
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Frequently asked questions
How do I convert ACOS to ROAS?
Divide 100 by the ACOS. A 25% ACOS is 100 ÷ 25 = 4× ROAS. Going the other way, divide 100 by the ROAS.
Why do platforms use different metrics?
Amazon grew out of a retail context where cost of sale is the natural frame; Meta and Google grew out of a media context where return on spend is. The information is identical.
Which is more useful?
ACOS is easier to compare against margin, since both are percentages of revenue. ROAS is easier to reason about when comparing channels. Most teams end up using both.
Is there a quick conversion to remember?
50% ACOS is 2×, 33% is 3×, 25% is 4×, 20% is 5%. Anything below 20% ACOS is a 5× or better return, which is rare on cold traffic.