Attribution & Tracking
Attribution Overlap Calculator
The Attribution Overlap Calculator quantifies how many conversions your ad platforms are double-counting by comparing the conversions Meta, Google, and TikTok each claim against your actual Shopify order count. It returns your overlap percentage, the number of duplicate conversions, your de-duplicated true revenue, the gap between blended (claimed) ROAS and true ROAS, and a suggested budget split. This tells you how much of your reported performance is real versus inflated by overlapping attribution windows.
Who it's for: DTC brands running three or more paid channels (Meta, Google, TikTok) at once that need to know their real, de-duplicated ROAS before reallocating budget.
How the Attribution Overlap Calculator works
You enter the conversions each platform reports (Meta, Google, TikTok), your actual Shopify order count, your average order value, your total ad spend, and your attribution model setup. The tool sums all platform-claimed conversions and subtracts your real Shopify orders to find the overlap count, then expresses that as a percentage of actual orders.
De-duplicated revenue is calculated from Shopify orders times AOV (the source-of-truth revenue), while claimed revenue uses the inflated total conversion count. Dividing each by total spend gives you blended ROAS (what platforms show) versus true ROAS (actual performance), making the inflation gap explicit.
The calculator identifies the platform claiming the most conversions as the likely top overlapper, suggests a budget allocation weighted by each channel's conversion share, and flags overlap above 50 percent as critical. Your selected attribution model (mixed, click-only, or short-window) drives a note on how much overlap that configuration typically adds.
The formula
Overlap count = (Meta + Google + TikTok conversions) - Shopify orders. Overlap % = (overlap count / Shopify orders) x 100. True ROAS = (Shopify orders x AOV) / total ad spend. Blended ROAS = (total claimed conversions x AOV) / total ad spend.
Frequently asked questions
What counts as attribution overlap?+
Overlap happens when more than one platform claims the same Shopify order. If Meta says it drove 500 sales, Google says 400, and TikTok says 300, that is 1,200 claimed conversions, but if Shopify only recorded 800 orders, 400 of those claims are duplicates. That 400 is your overlap, and it inflates every channel's reported ROAS.
Why does the attribution model setup change my overlap?+
Different windows count conversions differently. A mixed setup (7-day click 1-day view on Meta, 30-day on Google) catches the same buyer on multiple platforms and typically inflates overlap by 15 to 25 percent. Click-only attribution removes view-through credit and reduces overlap roughly 20 to 30 percent, while 1-day click windows cut it further but miss genuinely delayed conversions.
Should I just reallocate budget to the channel with the most conversions?+
Not directly. The channel claiming the most conversions is often the biggest over-attributor, not necessarily the most incremental. The suggested allocation in this tool is weighted by conversion volume as a starting point, but you should validate it with incrementality tests (such as geo holdouts) before making large budget shifts.
Where do I get the conversion counts for each platform?+
Meta Purchases are in Ads Manager, Google conversions are under the Conversions column filtered to your purchase action, and TikTok uses the Complete Payment metric. Your Shopify order count is in Analytics, Sales over time, Total orders. Use one consistent date range across all four so the overlap math is accurate.