Say you spent $1,200 on ads and those ads brought in $10,000 in sales. How much did you keep? Start with what the ads earned, then look at what it cost to do the work.
What did the ads bring in?
Divide the $10,000 in sales by the $1,200 in ad spend. That gives you 8.33× ROAS, or $8.33 in sales for every dollar you spent on ads.
What did it take to break even?
Say it cost $5,000 to deliver those $10,000 in sales. At that rate, half of each sales dollar goes toward doing the work. You need $2 in sales for each $1 in ads. One dollar pays for the work and the other pays for the ad. That gives you a 2× break-even ROAS, or a $2,400 sales target on $1,200 of ad spend.
How much was left?
Subtract the $5,000 delivery cost and the $1,200 ad spend from $10,000. That leaves $3,800 in campaign profit before fixed overhead. To work out your profit before taxes, account for fixed expenses such as rent and software subscriptions too.
Run your own numbers with the marketing calculators. Enter what you spent on ads, the sales those ads brought in, and what it cost to deliver them.