The short answer
Divide revenue attributed to your ads by the cost of those ads. A result of 4× means four units of revenue for every unit spent on advertising. It is a revenue-efficiency measure, not a profit calculation.
Choose the two inputs
| Input | What to use | What to check |
|---|---|---|
| Ad spend | Spend for the campaign or channel being reviewed | Include the full date range; use one currency. |
| Attributed revenue | Revenue assigned to the same advertising scope | Document attribution, refunds, tax and shipping. |
| Reporting period | A consistent date basis | An ad-click date report may differ from an order-date report. |
Store-wide revenue divided by one campaign’s spend is not that campaign’s ROAS. If the question is total-store efficiency, use a clearly labeled blended ratio. If conversion values are lead scores or modeled value, do not label them realized revenue.
Calculate the multiple and percentage
ROAS percentage = ROAS multiple × 100%
Illustrative example: a campaign has $1,200 of spend and $4,800 of attributed revenue. ROAS = $4,800 ÷ $1,200 = 4×. In percentage notation, 4 × 100% = 400%. The figures are teaching inputs, not campaign results or a target.
In a spreadsheet, put spend in A2 and revenue in B2. Use =IF(A2>0,B2/A2,NA()). Format that same numeric result as a percentage to display 400%; do not multiply by 100 again and also apply percentage formatting.
Interpret the result against costs
For an illustrative $100 order, 4× ROAS means $100 ÷ 4 = $25 advertising cost. If other order costs are $60, the order leaves $100 − $60 − $25 = $15 toward overhead and profit. If other costs are $80, it loses $5. The same ROAS supports different outcomes.
Calculate the offer’s break-even ROAS before calling the result good. An order-level threshold covers only the costs included, and attributed revenue does not prove that ads caused every sale.
Handle zero, missing and negative amounts
| Situation | Interpretation |
|---|---|
| Positive spend, zero revenue | ROAS is 0× if zero revenue is confirmed. Missing tracking data is not evidence of zero sales. |
| Zero spend | The ratio is undefined. Do not report infinity as a useful return. |
| Refunds exceed revenue in the selected period | A net-revenue ratio may be negative. Reconcile the order cohort; the public calculator accepts nonnegative revenue only. |
| Several campaigns | Add compatible revenue and spend first. Do not average ratios with unequal spend. |
Record a result someone else can reproduce
Keep the source, campaign scope, dates, currency, attribution rule, revenue adjustments and extraction date beside the two totals. If recent conversions are incomplete, label the result provisional. A reliable calculation starts with explainable inputs.
Platform reference: Google Ads conversion values explains value assignment. Check what your conversion value actually represents before using it as the revenue input.
Next reading
Examples are illustrative, not client results or benchmarks. The calculations use the inputs shown; real-world decisions depend on your records and assumptions. Report a correction.