ROAS is a ratio, not a profit
A ROAS of 3x means every unit of ad spend came back as three units of revenue. It does not mean you made money. Out of that revenue you still pay for the goods, the shipping, the payment fees and the returns, and only then find out whether the ads were worth it. That is why this calculator asks for your margin. Gross profit minus ad spend is the number that decides whether to scale a campaign, and break-even ROAS is the line you have to stay above for that number to be positive.
