ROAS explained

ROAS, return on ad spend, is the revenue your ads bring divided by what you spent on them. If you spend $1,000 on ads and they bring $4,000 in sales, your ROAS is 4, often written as 4:1 or 400 percent. It is the quickest way to see whether ads earn back their cost, but on its own it does not tell you whether they make money. For that, you need to compare it with your break-even ROAS, which comes from your profit margin.

That comparison is where many owners get caught out. A ROAS of 3 sounds healthy, yet for a business with a 25 percent margin it means losing money on every sale. Below I explain the formula, how to find your own break-even point, why the number in your ad platform is rarely the full story, and how to use ROAS when you sell services rather than products.

The formula

ROAS = revenue attributed to ads ÷ ad spend

Two details matter. Revenue here usually means sales value, before costs, taxes and returns. And ad spend usually means only what you paid the platform, not management fees or creative. Both choices make ROAS look better than real profitability, which is fine as long as you remember it.

Your break-even ROAS

To see whether ads are profitable, work out how much revenue you need for each dollar of ad spend just to break even:

Break-even ROAS = 1 ÷ gross margin

If your margin is 40 percent, every dollar of ad spend must bring at least $2.50 in sales just to cover the product cost and the ad. Anything above that is profit before overheads; anything below is a loss. Add management fees to the spend side if you want a stricter test.

This is why there is no universal "good ROAS". A jewellery brand with high margins and a grocery delivery service with thin ones live in different worlds.

ROAS, ROI and profit

• ROAS compares revenue with ad spend. Fast to calculate, ignores costs.
• ROI compares profit with total marketing cost. Slower, but answers the real question. I explain it in how to measure marketing ROI.
• Profit on ad spend (sometimes called POAS) uses gross profit instead of revenue. If you can pass profit values to Google or Meta, it lets the platforms optimize for margin instead of turnover.

Use ROAS to compare campaigns and catch problems quickly, and ROI to decide whether advertising is worth it overall.

Why platform ROAS misleads

The ROAS shown in Google Ads or Meta Ads Manager is the platform's view, and it tends to be generous:

• Attribution windows credit sales that happen days after a click, or after just seeing an ad.
• View-through conversions on Meta can count people who scrolled past your ad and bought later for other reasons.
• Double counting: Google and Meta can both claim the same sale.
• Brand searches: campaigns that capture people searching your business name show high ROAS for sales that would often have happened anyway.
• Modelled conversions, used when consent or browsers block tracking, are estimates.

A practical check is blended ROAS, sometimes called marketing efficiency ratio: total revenue divided by total ad spend across all channels for the month. If platforms report a combined ROAS far above your blended number, they are overlapping. Watch the blended number for decisions about total budget, and platform numbers for decisions inside each platform.

ROAS for service businesses

If you sell kitchens, renovations, legal work or cleaning contracts, sales happen offline, often weeks after the click. To calculate ROAS you need to connect leads to revenue:

1. Track each lead's source with proper conversion tracking and UTM tags.
2. Record in your CRM which leads became customers and what they paid.
3. Either import those values back into Google Ads and Meta, or calculate ROAS monthly in a spreadsheet or dashboard.

This is what end-to-end analytics means in practice: following a customer from the first click to the invoice. Once values flow back, you can use value-based bidding and stop optimizing for form fills that never buy.

First purchase vs lifetime value

ROAS on the first sale undervalues businesses with repeat customers. A cleaning company that wins a weekly client, a salon whose new customer returns every six weeks, or a store with loyal buyers earns far more over time than the first order shows. In those cases, judge ads by the value of a customer over a year or more. See customer lifetime value for a local business for how to estimate it without complex software.

A lower first-order ROAS can be perfectly healthy if the customers you win come back. The opposite is also true: a high first-order ROAS built on one-time bargain hunters may look better than it really is.

Target ROAS bidding

Google and Meta let you set a target ROAS and let the system bid toward it. It works when the account has reliable conversion values and enough volume; it struggles with a few conversions a month. Set the target close to what you already achieve, then raise it gradually. Setting it far above reality usually cuts volume sharply. Campaigns like Performance Max lean heavily on this; I discuss them in Performance Max for small businesses.

A real business that tracks sales from its site

Da Diego, a pizzeria in Żywiec, Poland, takes delivery orders through its own website with a CRM and ads behind it. The site now handles over PLN 15,000 a month (about C$5,500) in delivery orders. When orders flow through your own system, measuring ROAS becomes straightforward, because every order has a value and a source. The Da Diego case shows the setup.

Try it with your numbers

The ad ROI calculator lets you enter your margin, average order or job value and ad spend, and see where break-even sits. If you want me to set up tracking that shows real ROAS rather than platform optimism, GA4, Tag Manager and pixels are $650, and the first 30-minute consultation is free.