CalculateMyROI

Most marketing ROI calculators give you a percentage and leave you guessing. CalculateMyROI does the actual work, you plug in your campaign numbers and get ROI, customer acquisition cost, and projected customers in about 30 seconds. The free version covers the math most people do in spreadsheets but never bother to save. The paid version ($9.99, one time) runs your numbers through an AI analysis that flags where the unit economics break down, shows you the break-even path, and tells you what specifically to change. No signup. No subscription. No dashboard. Just paste your numbers and get a straight answer. Built as a side project by a software engineer tired of rebuilding the same Google Sheet every time he wanted to check if a campaign was worth running.