ROAS Formula: How to Calculate Return on Ad Spend (Excel)
Summary
ROAS = Revenue attributed to ads ÷ Ad spend. It shows how many dollars of revenue each ad dollar returns. A brand that spent $37,000 across Meta, Google and TikTok and attributed $123,040 of revenue has a blended ROAS of 3.33 (333%). Whether that is profitable depends on your gross margin.
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Return on ad spend (ROAS) formula
ROAS = Attributed revenue ÷ Ad spend (often shown as a ratio like 3.3 or a percentage like 330%)- Attributed revenue: Revenue credited to the ads under a stated attribution model and window, for example 7-day click in the ad platform or data-driven attribution in GA4.
- Ad spend: Media cost paid to the platform for the same period and campaigns. Agency fees and creative production are usually excluded and reported separately.
- Break-even ROAS: 1 ÷ Gross margin: the ROAS at which ad-driven gross profit exactly covers the ad spend.
How to calculate return on ad spend (ROAS) in Excel and Google Sheets
Excel, using the cells in the worked example below:
=SUM(C2:C4)/SUM(B2:B4)Worked example
A direct-to-consumer skincare brand reviews the last 30 days of paid media across three channels. Its products carry a 62% gross margin.
| Channel | Ad spend | Attributed revenue |
|---|---|---|
| Meta | $18,500 | $61,050 |
| Google Search | $12,200 | $50,020 |
| TikTok | $6,300 | $11,970 |
- Total spend = 18,500 + 12,200 + 6,300 = $37,000.
- Total attributed revenue = 61,050 + 50,020 + 11,970 = $123,040.
- Blended ROAS = 123,040 ÷ 37,000 = 3.33, or 333%.
- By channel (=C2/B2 filled down): Meta 3.30, Google Search 4.10, TikTok 1.90.
- Break-even ROAS at a 62% margin = 1 ÷ 0.62 = 1.61. TikTok clears it, but only just once returns and fees are counted.
Result: 3.33 ROAS (333%) blended across channels
How to interpret return on ad spend (ROAS)
There is no universal good ROAS: the threshold is set by your margin. A 62%-margin brand breaks even at about 1.6; a 25%-margin reseller needs 4.0 just to cover media. Platform-reported ROAS usually overlaps, because Meta, Google and TikTok can each claim the same order, so the sum of platform revenue often exceeds what your store actually booked. Use a single source of truth (GA4 or your order data) for blended ROAS, or track MER (total revenue ÷ total ad spend), and use platform ROAS only to compare campaigns inside one platform.
Common mistakes
- Adding up revenue claimed by each ad platform. Overlapping attribution double-counts orders; reconcile with GA4 or store revenue.
- Comparing ROAS across different attribution windows (1-day view vs 7-day click). State the window with every number.
- Judging ROAS without margin. A 3.0 ROAS loses money on a product with a 30% gross margin.
- Ignoring new vs returning customers. Retargeting existing buyers inflates ROAS; prospecting ROAS is lower but often more valuable.
Calculate return on ad spend (ROAS) with Better Analyst
Connect your data or upload a spreadsheet, then ask in plain English. Better Analyst writes and runs the calculation and shows the steps, so you can check the number.
- “Calculate ROAS by channel and campaign for the last 30 days from this ad spend sheet and our GA4 revenue.”
- “What is our break-even ROAS by product category given each category's gross margin?”
- “Show weekly blended ROAS and MER for the last six months.”
Usually calculated from: Google Analytics, Google Sheets, Google BigQuery, Snowflake.