To calculate ROAS, divide revenue from ads by the cost of those ads. The formula is simple, but the quality of the answer depends on the quality of your tracking. If the ad spend, revenue, and date range do not match, the result can mislead you.
You can use our free ROAS Calculator to do the math quickly, or you can calculate it manually in a spreadsheet. Either way, the goal is the same: understand how much revenue came back for every dollar spent on advertising.
The basic ROAS formula
The standard ROAS formula is:
ROAS = Revenue from ads / Ad spend
If a campaign spends $500 and produces $2,000 in revenue, the ROAS is 4. That is usually written as 4x ROAS. You can also show it as a percentage by multiplying by 100, which would be 400 percent.
Why the date range matters
ROAS only makes sense when spend and revenue come from the same reporting window. If you use last week's ad spend with this month's revenue, the number may look better or worse than reality.
Step-by-step guide
Step 1: Choose the campaign
Pick one campaign, ad set, channel, or account. Mixing everything together can hide weak areas.
Step 2: Find total ad spend
Use the exact cost shown in your ad platform for the same period.
Step 3: Find revenue from ads
Use tracked sales, ecommerce revenue, or estimated lead value connected to the campaign.
Step 4: Divide revenue by spend
This gives you the ROAS number. A result of 3 means the campaign generated three dollars in revenue for every dollar spent.
Real example
A brand spends $1,200 on a paid search campaign and tracks $5,400 in sales. The calculation is $5,400 divided by $1,200, which equals 4.5x ROAS. As a percentage, that is 450 percent.
Common mistakes
- Using total store revenue instead of revenue from ads.
- Forgetting refunds, cancellations, or duplicate purchases.
- Comparing ROAS across channels with different attribution rules.
- Assuming high ROAS always means high profit.
Conclusion
Learning how to calculate ROAS gives you a cleaner way to judge paid campaigns. Keep the formula simple, keep your data consistent, and use the result as a decision signal rather than the only metric that matters.
CTA: Try our free ROAS Calculator.