How to Calculate Marketing ROI (With Real Campaign Examples)

September 5, 2026 · 5 min read

Marketing spend without ROI tracking is guessing with money. Every dollar you spend on ads, content, SEO, or email should produce a measurable return. If you cannot calculate what came back from what you put in, you cannot know which channels to scale and which to cut.

The Basic ROI Formula

ROI = ((Revenue from campaign - Cost of campaign) / Cost of campaign) × 100. Spent $2,000 on Google Ads and generated $8,000 in sales? ROI = ((8,000 - 2,000) / 2,000) × 100 = 300%. For every dollar spent, you got three dollars back in profit.

ROI by Marketing Channel

Paid search (Google Ads): average ROI of 200-400%. Email marketing: average ROI of 3,600% ($36 for every $1 spent). SEO: average ROI of 275-1,200% (varies wildly by industry and timeline). Social media ads: average ROI of 100-300%. These are averages — your results depend on execution.

What Most People Get Wrong

The biggest mistake is not including all costs. Your Google Ads ROI is not just ad spend — include the cost of someone managing the campaigns, landing page design, and any tools or software. The second mistake is attributing all revenue to the last click. A customer might discover you through SEO, engage via email, and convert through a retargeting ad.

When ROI Takes Time

SEO and content marketing have negative ROI for the first 3-6 months. You invest upfront and see returns over months and years. Judging these channels on 30-day ROI will make you abandon them prematurely. Track ROI over 6-12 month windows for organic channels.

Try It Now

Our free ROI Calculator handles this instantly — no signup, no limits.

Also useful: our Percentage Calculator for related calculations.