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How much of your Shopify ad spend is wasted?
Enter four numbers from your Meta Ads, Google Ads, and Shopify dashboards. This calculator applies published industry benchmarks for brand cannibalization, creative fatigue, and channel overlap to estimate your monthly waste and the gap between your reported ROAS and your true ROAS.
Runs in your browser. No data leaves your device. Built by Ripplux — the truth tool for Shopify merchants.
How the calculator works
Most Shopify merchants running paid ads see two numbers: a reported ROAS from Meta (say, 3.4x) and a reported ROAS from Google (say, 4.1x). Their bank account shows a different story. The gap between those platform numbers and reality has three measurable causes — and this calculator quantifies all three.
1. Brand cannibalization (18–25% of spend)
Ad spend that converts customers who would have purchased organically. Most common in brand-search campaigns — you pay Google to show an ad when someone searches your store name, but they were already coming to buy. The calculator applies a conservative 22% baseline across total paid spend. Deep dive: what is ad cannibalization?
2. Creative fatigue (12–22% of spend)
Ads lose effectiveness as audiences see them repeatedly. Peak CTR degrades over weeks; cost per result climbs; incremental revenue declines while spend holds constant. The calculator uses a 17% baseline — the midpoint of published DTC Shopify data. More: how to detect creative fatigue or try the fatigue checker.
3. Channel overlap (8–15% of cross-platform conversions)
When a customer sees a Meta ad Monday and clicks a Google ad Friday before buying, both platforms claim the full conversion. The calculator estimates overlap proportionally to the smaller of Meta vs Google spend, because that's the bound where double-counting can occur. Deep dive in the blog post on channel overlap and double attribution.
Reading your result
The headline number is your estimated monthly waste — the dollars that are not buying you incremental revenue. The per-category breakdown (cannibalization, fatigue, overlap) tells you which lever to pull first. The true ROAS is your reported ROAS after removing waste — usually 30–50% lower than the platform number.
These are industry-average estimates. Your actual numbers could be higher or lower depending on your audience mix, creative refresh cadence, and campaign structure. The only way to know for sure is to run real incrementality experiments — which is what the paid Ripplux platform does.
Related tools and reading
Frequently asked questions
- How accurate is this calculator?
- Directional. It applies published industry benchmarks to the four numbers you enter, which is enough to tell if your real number is closer to $500/mo or $5,000/mo — but can be off by 20–40% vs a connected-data audit.
- Do I need to sign up or connect anything?
- No. This entire calculator runs in your browser. No data is sent anywhere. The URL encodes your inputs so you can share or come back to the same result.
- What if only Meta OR only Google?
- Leave the other platform at 0. The calculator still estimates cannibalization and fatigue from your single-platform spend. Channel overlap will be 0 (no overlap possible).