Return on ad spend

Return on ad spend, commonly shortened to ROAS, compares the value attributed to advertising with the amount spent on that advertising. It is often used in ecommerce reporting to describe how much recorded revenue a campaign generates for each pound of media spend.

A ROAS figure needs a definition. Some reports use order revenue; others use configured conversion values, which may be estimates. The number becomes useful when the business understands what value is included, how attribution works and which costs sit outside the calculation.

How do you calculate ROAS?

The basic formula is: ROAS = attributed revenue or conversion value divided by advertising spend. Multiply the result by 100 to express it as a percentage.

If a campaign spends £1,000 and is attributed £5,000 in revenue, its ROAS is 5:1, often written as 5x or 500%. These are different expressions of the same relationship.

Keep the period and scope consistent. Comparing a month's media spend with revenue from a different cohort can produce a misleading result. Record whether the calculation concerns one campaign, one platform or the overall advertising programme.

Is ROAS the same as profit?

No. Revenue is not profit, and media spend is not the whole cost of selling. Product costs, delivery, payment processing, returns, discounts and other operating costs can change the commercial meaning of the same ROAS.

Two shops can report identical advertising returns while retaining very different amounts from each order. A business with a lower contribution margin needs a different level of revenue to cover the same advertising expense.

Use ROAS alongside contribution and customer information. It is a useful lens on advertising value, but it should not be asked to describe the entire financial performance of the business.

What is a good ROAS?

There is no universal target that works for every company. The answer depends on margins, the definition of value and the economics of acquiring the customer.

An established repeat customer and a new customer may also have different implications. A business might accept a lower immediate return to acquire suitable first-time buyers, provided the assumption about future value is supported by evidence.

Start by calculating what the business can afford. Then consider the role of the campaign, the reliability of measurement and the time over which its return should be assessed.

How do you estimate a break-even ROAS?

A simplified calculation uses the contribution margin before advertising. If that margin is 40%, a revenue ROAS of 2.5x would cover media spend in that simplified model: one divided by 0.40 equals 2.5.

For example, £2,500 in revenue at a 40% contribution margin produces £1,000 before advertising. If the associated media spend is also £1,000, nothing remains from that contribution after media.

This illustration excludes any costs not included in the margin definition. It is a planning calculation, not proof that the whole company has broken even. Specify the included costs before using it as a target.

Why do platforms report different ROAS figures?

Platforms can use different attribution windows and methods. They may also observe different parts of the journey. An email, a search advert and a social advert can all influence the same eventual order.

Do not add every platform's claimed revenue together and assume the total represents distinct sales. Compare the claims with actual business revenue and understand where credit overlaps.

Differences can also arise from returns, cancelled orders, currency handling, consent-related gaps and the timing of reporting. Investigate these definitions before treating a discrepancy as evidence that a campaign has changed.

ROAS versus incremental return

Attributed return describes the sales a reporting method credits to advertising. Incremental return asks how much additional value advertising caused compared with what would have happened without it.

Those are different questions. A campaign reaching people already intending to buy may receive strong attribution without creating an equivalent amount of additional demand.

Incrementality may require a suitable experiment or another carefully designed evaluation. Routine platform reporting alone cannot establish the counterfactual. Be clear about which kind of claim the evidence supports.

How can a business improve ROAS?

Begin by checking value tracking and order quality. Then investigate the audience, offer and destination. Improving the relevance of the campaign or the clarity of the landing page may improve the economics.

Changes to average order value or product mix can also affect the ratio. Assess whether they create worthwhile contribution rather than simply increasing recorded revenue.

A higher ROAS can sometimes result from reducing spend to a narrow audience. That may improve the ratio while reducing total profit or limiting growth. Evaluate the amount of useful value generated as well as the efficiency percentage.

Is ROAS useful for lead generation?

It can be, but only when the value assigned to leads is meaningful. Giving every form submission an arbitrary revenue value creates a number that looks financial without being grounded in actual sales.

Where possible, connect qualified opportunities and completed sales with their acquisition sources. If the business uses expected values, document the assumptions and update them as evidence improves.

Cost per acquisition can provide another view, especially when lead quality and sales outcomes are measured separately.

For the platform definition, see the Google Ads glossary. A useful report explains the value, attribution and cost definitions beside the result.