ROAS formula: how to calculate return on ad spend honestly

What is the ROAS formula?

ROAS, or return on ad spend, is the revenue an ad campaign brings in for each dollar spent on it. The math is one division: revenue from advertising divided by ad spend. Shopify's guide to return on ad spend writes it that way, and so does every advertising platform.

ROAS is a simple marketing metric, and Amazon's advertising guide describes it as a measure of an advertising campaign's effectiveness. The platforms differ only in how they show the answer.

Google writes a target ROAS as a percentage: $5 in sales on $1 of ad spend is 500%. Meta writes it as a decimal, so a 110% return is a ROAS goal of 1.100. Amazon uses ACOS, advertising cost of sales, which is the same math turned upside down.

A worked ROAS calculation

Here are three example campaigns with made-up numbers, run for the same two weeks:

The blended 2.46 looks fine and hides a campaign returning $1.50 per dollar spent. Always calculate ROAS for each ad campaign before you look at the total.

“by aggregating products/services into lumpy groups, it can give a misleading sense of success.”

Avinash Kaushik, author of the Occam's Razor analytics blog, The Most Important Business KPIs

He was describing ROAS itself. A single store-wide number is the lumpiest group of all.

How do you calculate ROAS step by step?

Pick one campaign and one date range, then pull each number from the system that actually records it.

1. Choose the campaign and the dates. Use at least a full week. Meta's help center says day-to-day ROAS naturally fluctuates and suggests judging weekly averages.
2. Pull the ad spend. Take Amount spent from Meta Ads Manager, or the cost from your Google account, for the same dates. Add any fee you pay someone to run the campaign.
3. Pull the revenue from Shopify. Use the Total sales by referrer report, or a marketing report filtered to the campaign's UTM tags, for the same dates.
4. Divide revenue by spend. In Excel or Google Sheets, with revenue in B2 and spend in C2, type =B2/C2.
5. Compare the result with your break-even ROAS. Above it, the campaign covers its products and its advertising. Below it, every order it brings in costs you money.

Shopify will not do the division for you on paid social and search. Shopify's help center says Facebook and Google campaigns on its Growth page don't display metrics such as cost or ROAS, and points you back to Meta and Google. So the spend comes from the ad platform and the revenue from Shopify.

Which numbers go into a ROAS calculation?

Two numbers, and each has a trap. The revenue should be the sales your store recorded. The spend should be everything the campaign cost.

The revenue

Use the sales Shopify credits to the campaign, not the ad platform's own figure. Meta's Purchase ROAS metric is purchase conversion value divided by amount spent, and Meta says statistical modeling may fill in events it cannot count directly.

Meta's attribution settings can also credit a purchase made within one day of someone simply seeing an ad. That is one way a dashboard ROAS ends up higher than the store's own count.

Shopify's Total sales by referrer report shows the last interaction referrer, the site a buyer came from just before ordering. It is the store's own record of money in. Tag every ad link with UTM parameters, short tags at the end of a link, because Shopify attributes traffic that carries a utm_campaign parameter to marketing.

Pick one revenue figure and keep it: Shopify’s sales report definitions put taxes, duties, shipping charges and fees inside total sales and leave them out of net sales, and the Google & YouTube app sends purchase values without shipping or tax.

“The system is only as good as the data that you get.”

Carlo Buchmann, a Google product manager for bidding and budgets, Google's podcast episode on budgets and bidding, March 2026

He meant the conversion values a store sends Google for bidding. It applies just as well to your own ROAS: a platform that counts its own conversions is grading its own homework.

The ad spend

ROAS is only as honest as the costs you count. Shopify's guide notes that the standard calculation only includes direct advertising spend, while some brands add management fees and creative. To decide whether the advertising pays, count everything spent to run it.

If Meta's dashboard shows a healthy number and your bank balance disagrees, you are not imagining it. The two are usually counting different things.

What did the reports show on one store?

Before the work began, one direct to consumer store on Shopify paid about $1,700 a month for Facebook advertising: $1,200 in ad spend plus $500 to a prior vendor. Leave the vendor fee out, and every campaign looks better than the business result.

Shopify's sales attribution report for the 90 days before September 3, 2026 then showed where the orders really came from. Paid Facebook and Instagram brought $2,322 from 9,214 visits and 9 orders. Google search, not paid, brought $8,316 from 1,720 visits and 24 orders: more than 3.5 times the sales from under a fifth of the traffic.

What that does not prove: the report credits each order to the visit it came from, so an ad that introduced a buyer who later searched Google gets no credit. It does show why the revenue in any ROAS should come from the store's reports.

The cold and warm audience results are in the Facebook break-even math, and the full receipts are in the case study.

What is break even ROAS?

Break-even ROAS is the return on ad spend at which a campaign exactly covers the cost of the products it sells and the advertising that sold them. Shopify's break-even guide works it out as 1 divided by your gross profit margin, the share of each sale left after product, shipping and fees.

In Shopify's example, a product sells for $100 and its variable costs are $60, so the margin is 40 percent and break-even ROAS is 2.5. Below $2.50 in sales for every $1 of ad spend, the orders cost more than they earn.

The same ROAS can make or lose money depending on the margin. Here is one example: $100 of ad spend returning $300 in sales, a 3:1 ROAS, at four margins.

Same ROAS, four different businesses. That is why nobody can name a good ROAS for your store without knowing your margin.

What if Facebook and Google both claim the same sale?

Then adding up each platform’s results counts that order twice. Each platform credits sales by its own rules and cannot see the other’s ads, so one order can show up in both.

Judge the whole program with blended ROAS instead: the store’s own sales divided by everything spent on ads. Shopify’s guide to the marketing efficiency ratio, or MER, calls this a business-level view.

An example with made-up numbers, for one month:

The dashboards claim $2,500 more than the store sold. At a 40 percent margin, break-even is 2.5, so a blended 2.29 means the ads do not pay for themselves even if every sale is credited to them. Then use each campaign’s ROAS, counted in Shopify’s referrer report, to decide where the next dollar goes.

What is a good ROAS?

A good ROAS is one that sits comfortably above your break-even ROAS after every cost of the ad campaign. There is no universal number, because margins differ.

Benchmarks help only as context. Triple Whale's Meta benchmarks, updated August 18, 2026, cover more than 40,000 brands using its software from August 1, 2025 to July 31, 2026. They put the median ROAS at 1.88.

At a 40 percent margin, that median would sit under the 2.5 needed to break even. It is Triple Whale's figure for its customers, not a target for your store.

“You could put a dollar or two to work in Facebook and Google”

Matt Scanlan, founder of Naadam, on Shopify Masters, Shopify's break-even ROAS guide

He was describing a less crowded time, when it came back as eight to 16. Shopify's guide says those outsized returns have largely vanished, which is why the break-even number matters more now than it did then.

What is the difference between ROAS and ROI?

ROAS is a sales metric: it measures revenue against ad spend. ROI, return on investment, measures profit against the whole investment. Google's glossary defines ROI as how much profit you've made from your advertising and free product listings compared with what you spent on them.

Google's own example shows the gap. A product costs $100 to make and sells for $200. The campaign sells six: $1,200 in sales, $600 in product costs and $200 in ad costs.

Google puts the ROI at 50 percent. The ROAS on the same numbers is $1,200 divided by $200, or 6.

Use ROAS to compare one ad campaign with another. Use ROI, or break-even ROAS, to decide whether the investment is profitable at all.

How do Google and Meta use a target ROAS?

Both platforms can bid toward a ROAS you set, and both measure performance with their own count of conversion value.

• Google's Target ROAS sets bids to maximize conversion value while trying to hit your target. Search and Shopping campaigns need at least 15 conversions in the past 30 days to use it, and Google warns that a target set too high may limit the traffic a campaign gets.
• Meta's ROAS goal keeps the weekly average return near the goal you set, once you choose to maximize the value of conversions as the performance goal. Meta says it works best when an ad set gets at least 50 to 100 conversions a week.

As of September 2026, Google's help center says the strategy is being renamed from Maximize conversion value with a Target ROAS to plain Target ROAS. It also says a bidding update for budget-limited campaigns, starting August 17, 2026, may cause temporary swings in campaigns that use Target ROAS.

Base any target on your break-even ROAS. Then check it against Shopify each month: if the platform reports higher revenue than Shopify credits to it, raise the target to cover the gap.

What does ROAS not tell you?

• Whether the sale would have happened anyway. Shopify's ROAS guide notes that a high ROAS on Google search campaigns may come from customers who had already decided to buy and were searching for the product. Retargeting ads and brand searches look strong for the same reason.
• Whether the customer is new. A campaign that mostly reaches past buyers can post a strong ROAS and bring in no new customers.
• What the ad started. A last interaction report gives no credit to the ad that first introduced a buyer who came back later through Google or an email.
• Profit. ROAS leaves out product costs, shipping and fees. Only break-even ROAS or ROI brings them in.

Two more views help. Shopify's marketing reports can switch to a first click model, which credits the channel a customer first came through.

Meta now offers an incremental attribution model that predicts whether a conversion was caused by an ad. That is still Meta's model of Meta's effect, so keep Shopify's reports as the tiebreaker. For where each report lives, see which Shopify reports show where sales come from.

How do you improve ROAS without raising the budget?

Fix the math first, then the store, then the traffic mix. A simple order:

1. Recalculate every campaign honestly. Use Shopify's revenue and the full advertising cost, then pause campaigns that stay under break-even.
2. Fix what happens after the click. Clear product pages, shipping costs shown early and a checkout that works raise revenue from the same budget.
3. Stop paying for buyers who would find you anyway. Products that show on Google for free through Google's free listings, and emails that actually send, carry more of the sales.
4. Recheck performance every month. ROAS drifts as the cost of Facebook advertising rises and audiences wear out.

That is the order The Traffic to Sales Method follows. A Traffic to Sales Check reads Shopify, Google and email side by side, then Get Found, Get Names and Get Orders build the channels that do not bill per click.

More on that in how to increase sales without more ad spend, and on choosing a paid channel in how Google and Facebook compare for a store.

What does it look like when the numbers are honest?

You know which campaigns pay for themselves and which only look good in their own dashboard. The ROAS formula never changes. What changes is where the numbers come from and what you compare them with.

Paid advertising becomes a lever you pull on purpose, while Google and email bring in orders you do not pay for one click at a time. If you want those numbers pulled from your own accounts, the free Traffic to Sales Check puts Shopify, Google and email side by side, and a Shopify store audit goes through the store campaign by campaign.

Does this sound like your store?

If it does, the service that fixes it is Shopify store audit. You can see the before and after on one store in the case study.