Return on Ad Spend is the full name of the metric abbreviated as ROAS. See the ROAS entry for the complete definition, formula, benchmarks, and optimization guide.
Quick Reference
Formula: ROAS = Ad Revenue ÷ Ad Spend
Inverse of ACOS: ROAS = 1 ÷ ACOS (expressed as a decimal)
| ACOS | ROAS |
|---|---|
| 25% | 4× |
| 33% | 3× |
| 50% | 2× |
| 100% | 1× (break-even on ad spend) |
ROAS is the standard metric in Google Ads, Meta Ads, and most DTC advertising contexts. Amazon sellers more commonly use ACOS, which expresses the same relationship inverted (as a cost percentage rather than a revenue multiple). Both metrics measure the same efficiency — they are mathematically equivalent.