Google Ads ROI Calculator
Plug in ad spend and revenue. Get ROAS, net profit, ROI %, and the breakeven ROAS your margin demands. No email, no signup, no tracking.
Pawel “Vilo” Wilk — Google Ads specialist. This is the same math I use at the start of every audit to anchor the conversation.
Your numbers
Total Google Ads spend over the period you're measuring.
Revenue attributed to Google Ads (last-click or your model of choice).
Variable cost as a % of revenue. E-com physical: 30-50%. SaaS: 10-25%. Services: 25-50%.
Results
How to read these numbers
ROAS tells you how many dollars of revenue every dollar of ad spend produced. It is operational — it ignores your margin. A 4x ROAS sounds great until you remember that on a 25% margin business it just barely breaks even.
Breakeven ROAS is the floor: the ROAS at which gross profit equals ad spend. Calculate it as 1 / margin. A 30% COGS / 70% margin business breaks even at 1.43x ROAS. A 60% COGS / 40% margin business breaks even at 2.5x ROAS. Any reported ROAS without context of margin is half a number.
Net profit is the dollar number that pays your salary. Gross profit (revenue × margin) minus ad spend. If it's negative, you're losing money on every click — which is fine when paying for new-customer acquisition with positive lifetime value, but catastrophic if those customers don't return.
ROI % is net profit divided by spend, expressed as a percentage. A 100% ROI doubles your money. The mistake most operators make: bragging about high ROI on tiny spend rather than scaling spend to a sustainable ROI floor and capturing far more total profit at lower margin.
Want this math run on your live Google Ads data?
A Perfoads audit pulls actual ROAS, breakeven, and waste-spend numbers from your account in 5 minutes — read-only access, prioritized fix list, and the “PerfoAds Read” of what's actually moving the needle.
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