How do I calculate marketing ROI?

Marketing ROI is the return divided by the cost. Take the gross profit attributable to marketing, subtract the full marketing cost, and divide the result by that cost. A campaign that costs $10,000 and produces $35,000 of attributable gross profit returns 2.5 to 1. The arithmetic is the easy part. The word doing all the work is attributable, and that is where most published ROI numbers fail.

Two decisions determine whether the number means anything. Use gross profit, not revenue. A $35,000 job carrying $20,000 in cost of goods did not return $35,000 on the campaign that produced it; revenue-based ROI flatters every number it touches. And count the whole cost. Ad spend is the visible part—agency fees, software, creative production, and your own people’s hours belong in the denominator too. A campaign that reads 4 to 1 on ad spend alone is often closer to 2 to 1 fully counted, and 2 to 1 may still be good.

Where this matters

Attribution is honest when the path is short and tracked—a search ad, a call, a signed job. It turns dishonest when cycles are long, when referrals and repeat business carry earned trust, or when a buyer reads for months and arrives typing the company’s name. Some of marketing’s return shows up as pipeline nobody can trace. Compute ROI only where attribution is defensible, say what was left out, and resist inventing precision for the rest. As a working benchmark, a fully counted 5 to 1 is commonly treated as strong for small-business marketing. Long-cycle businesses should expect the number to arrive late; a single quarter can neither prove nor disprove it. Measure on the calendar the business actually sells on.

For the spend side of the same arithmetic, see the small-business marketing budget guide.