ROAS (Return on Ad Spend)

ROAS shows how efficiently a campaign, a channel or an entire ad account turns budget into revenue. The formula is simple: revenue attributed to ads ÷ ad spend. The result is expressed either as a ratio (for example 4) or as a percentage (400%); a ROAS of 4 means every 1 unit spent returned 4 units of revenue.

ROAS is one of the most widely used metrics in performance marketing and the basis of target ROAS bidding strategies on platforms such as Google and Meta. However, because revenue is not the same as profit, and because which ad receives the revenue depends on the attribution model, reading ROAS correctly requires context.

• Attributed revenue: Sales revenue credited to ads; the attribution model and window used should be stated.
• Ad spend: The media budget paid to platforms; agency, creative and tool costs are usually excluded.
• Gross margin: How much of the revenue turns into profit; break-even ROAS is calculated from this margin.
• Returns and cancellations: If they are not deducted from gross sales, ROAS looks higher than it is.
• Time frame: For businesses with long buying cycles, short-term ROAS gives an incomplete picture.

Think of a shop selling several product categories. ROAS looks high across the account and the team decides to raise the budget. Broken down by category, however, most of the high ROAS turns out to come from low-margin products, while high-margin products are running on too little budget.

This is where break-even ROAS comes in: break-even ROAS = 1 ÷ gross margin. For a product with a 25% gross margin, break-even ROAS is 4; every sale below that value loses money. When category targets are set with this logic, the budget is allocated by profit rather than revenue.

To calculate it, take the ad-driven revenue and the ad spend for the same period and divide revenue by spend. What matters is being clear about where the revenue figure comes from: the advertising platform's own report, an independent analytics tool or the CRM. Because platform reports can credit the same sale to more than one channel, the sum of channel ROAS figures often exceeds the real total.

When interpreting it, ROAS is read alongside the break-even value, the split between new and returning customers, and return rates. Metrics such as MER, which compares total marketing spend with total revenue, and profit-based POAS complete the picture.

ROAS looks only at the relationship between ad spend and revenue. ROI (return on investment) takes all costs into account, including product cost, operations, agency and tools, and compares net profit with the investment. A campaign with high ROAS can produce negative ROI because it sells low-margin products. ROAS is used to compare campaigns and for day-to-day optimisation; ROI shows whether the business is actually making a profit. In our performance marketing work we build both views together.