Measurement
How to calculate true ROAS on Shopify
"Platform ROAS," "blended ROAS" and "true ROAS" get used interchangeably, but they're three different calculations that can produce three noticeably different numbers from the same spend and the same orders.
Platform ROAS: what Meta or Google reports on its own
This is the ROAS shown inside Ads Manager or Google Ads itself — attributed revenue from that platform's own model, divided by that platform's own spend. It only counts orders that platform's attribution decided to credit to itself, using its own window and model. It's the least reliable of the three for judging total business impact, because it was never designed to represent anything beyond that platform's own view.
Blended ROAS: combining spend against attributed revenue
Blended ROAS adds Meta and Google spend together and divides by their combined attributed revenue. It's a step closer to reality, but it inherits a problem from both platforms: because Meta and Google each independently attribute some of the same orders to themselves, simply adding their reported revenue together double-counts the overlap. Blended ROAS calculated this way is still usually inflated — just less inflated than either platform's number alone.
True ROAS: total ad spend against actual Shopify revenue
True ROAS steps outside platform attribution entirely: total ad spend across every channel, divided by actual Shopify revenue for a comparable period — net of refunds, with discounts and tax treated consistently. It doesn't try to credit specific orders to specific ads. It answers a plainer question: for what you spent on advertising, how much did the store actually take in. That's closer to what MER measures, covered in more detail on the MER vs ROAS page.
Refunds, discounts, tax and revenue windows
Even "actual Shopify revenue" isn't a single obvious figure. Gross sales, net sales after discounts and refunds, and revenue including tax and shipping can each tell a different ROAS story from the same underlying orders. A refund processed two weeks after the sale rarely gets reflected back into platform-reported ROAS at all, but it should reduce true ROAS if you're calculating it from net revenue. Decide which revenue figure you're using and apply it consistently — mixing gross platform numbers against net Shopify numbers is a common way the comparison gets distorted without anyone noticing.
What Attribix shows instead
Attribix combines Meta and Google spend with net Shopify revenue and shows blended ROAS and true ROAS alongside each platform's own reported number — so the gap between them is visible, rather than something you'd only notice by reconciling spreadsheets manually.
See your blended and true ROAS
Connect your store and ad accounts to compare platform-reported ROAS against actual Shopify revenue.