The formula
ROAS = revenue ÷ spend · ROI = (margin − spend) ÷ spend × 100
What it means
ROAS measures how much revenue each unit of spend brings in, but revenue is not profit. If you sell on a 30 % margin, a ROAS of 2 means that for every 1,000 spent you take 2,000, of which only 600 is margin: you lose 400.
How to work it out by hand
- Work out the margin that revenue leaves
- Subtract the ad spend
- Divide by the spend and multiply by 100
What is worth knowing
The minimum ROAS to break even is the inverse of your margin: on a 30 % margin you need a ROAS of 3.33 just to draw level. On 50 %, of 2. That number is the one to keep in front of you when reading any ad dashboard, because the platforms always show ROAS and never your margin.