ROI vs ROAS: The Two Numbers Every Brand Should Track
ROI and ROAS get used almost interchangeably in casual conversation about campaign performance, but they're not quite the same number, and mixing them up in a report can genuinely confuse a conversation about whether a campaign worked. The good news is that once you see how they relate, converting between them — or picking the right one to quote — is straightforward.
The two formulas
ROAS (return on ad spend) is revenue divided by spend, expressed as a multiple:
ROAS = Revenue ÷ Spend
A ROAS of 3 (often written "3x") means every dollar spent generated three dollars of revenue.
ROI (return on investment) is profit — revenue minus spend — divided by spend, expressed as a percentage:
ROI% = (Revenue − Spend) ÷ Spend × 100
The key difference: ROAS treats the original spend as part of the return, while ROI subtracts it out first. That's why a ROAS of 3x and an ROI of 200% describe the exact same campaign — ROI has simply netted out the 1x you get back just for breaking even.
Worked example: revenue given directly
A campaign spends $1,000 and generates $2,500 in attributed revenue:
- Profit: $2,500 − $1,000 = $1,500.
- ROI: $1,500 ÷ $1,000 × 100 = 150%.
- ROAS: $2,500 ÷ $1,000 = 2.5x.
Worked example: building revenue from conversions
Often you don't have a clean "revenue" figure — you have a conversion count and a value per conversion. Say a campaign spends $500 and drives 50 conversions worth $20 each:
- Revenue: 50 × $20 = $1,000.
- Profit: $1,000 − $500 = $500.
- ROI: $500 ÷ $500 × 100 = 100%.
- ROAS: $1,000 ÷ $500 = 2x.
- Cost per conversion: $500 ÷ 50 = $10.
The "value per conversion" here could be an actual average order value for e-commerce sales, or an internal figure a business assigns to a lead or sign-up based on typical downstream value — either way, the ROI and ROAS math is identical once that number is set.
When each number is more useful
ROAS tends to be the number media buyers and platforms quote directly, since it maps cleanly onto "how much did this ad spend return." ROI tends to read more naturally as a profitability figure, since a 50% ROI communicates "half again what I spent, as profit" more intuitively than "1.5x." Reporting both avoids ambiguity — and it's worth explicitly naming which one you're using, since "3x return" and "300% ROI" sound similar but are very different numbers (300% ROI is actually 4x ROAS).
Converting between the two
Because both formulas share the same revenue and spend inputs, converting between them is direct arithmetic rather than a separate calculation:
- ROAS to ROI%: subtract 1 from the ROAS multiple, then multiply by 100. A 2.5x ROAS becomes (2.5 − 1) × 100 = 150% ROI.
- ROI% to ROAS: divide the ROI percentage by 100, then add 1. A 150% ROI becomes (150 ÷ 100) + 1 = 2.5x ROAS.
Keeping this conversion handy is useful when a brand quotes one figure and an internal report tracks the other — it avoids re-deriving revenue and spend from scratch just to compare two numbers that were always describing the same outcome.
What these numbers don't capture
Both formulas here use campaign spend as the only cost input, which matches how ROI and ROAS are conventionally reported for marketing performance — but neither one subtracts product cost of goods, agency fees, or overhead. A campaign can show a strong ROAS on paper while still being unprofitable once those additional costs are factored in. Attribution is another blind spot: revenue "from" a campaign usually depends on a tracking model that credits a sale to a particular touchpoint, and different attribution windows or models can produce meaningfully different revenue figures for the exact same campaign. And not every campaign is run purely for immediate revenue — brand awareness, list-building, and reach campaigns often generate value that doesn't show up in this formula at all. Judge the metric against the campaign's actual goal, and treat the attribution model behind the revenue number as part of the result, not a neutral fact.
Try it yourself
The Campaign ROI Calculator computes both figures from either revenue directly or from conversions and a per-conversion value, along with cost per conversion.