Free tool · 2026
iOS Attribution Loss Calculator
iOS 14.5+ broke pixel fidelity. Your platforms under-report conversions, your reported ROAS looks worse than reality, and your bid targets quietly under-buy iOS audiences. Plug in your numbers — we'll estimate the gap and the uplift multiplier to apply.
Your numbers
Pull from your last 30 days of Meta / Google reporting.
Funnel type
Web purchases are partly recovered via CAPI / server-side. Typical range: 20–40%.
Total purchases / signups in your dashboard
Total ad spend across all platforms
Total attributed revenue (in-platform)
Typical: 50–60% for US; 35–45% globally; 25–35% emerging markets
Override the default if you've measured iOS lift directly
Adjusted ROAS estimate
Apply a 1.20x uplift to your reported ROAS to approximate reality.
The math (in plain English)
When an iOS user opts out of ATT (App Tracking Transparency), their conversion event doesn't get attributed back to the ad click. The platform's reporting is missing that conversion entirely, OR the event is reported but the attribution model can't link it to the right ad.
The math:
true conversions = reported / (1 − iOS_share × loss_rate)Apply the resulting uplift multiplier to your platform-reported ROAS to estimate your honest cross-platform ROAS — useful when you're reconciling Meta-reported ROAS against GA4 or Stripe revenue.
Two important caveats. First, the loss-rate defaults are industry averages — your specific stack (CAPI enabled? SKAdNetwork postbacks configured?) can move the number by 20+ percentage points. Second, never just multiply bid targets by the uplift and hope — run a Meta Conversion Lift or geo-holdout test to validate before you commit budget. Read the attribution playbook for the full framework.
Frequently asked
›What is iOS attribution loss?
Since iOS 14.5 (April 2021), apps must request explicit permission to track users across other apps and websites (ATT — App Tracking Transparency). Most users decline. When they do, their conversion events can't be tied back to ad clicks via traditional pixel/cookie attribution. The platform either doesn't report the conversion at all, or reports it as a 'modeled' conversion with reduced certainty. The result: reported ROAS systematically understates reality, especially for iOS-heavy audiences.
›Typical loss rates by funnel type in 2026?
Web ecommerce with CAPI (Conversions API): 20-40% loss on iOS conversions. Mobile app installs and post-install events: 40-70% — SKAdNetwork is much coarser than the old IDFA-based attribution. Lead-gen / B2B: 15-30% — form submits are usually server-side via offline conversions, which iOS doesn't break. Numbers vary by stack, audience age (younger skews more iOS), and how cleanly your CAPI is wired.
›Should I increase my bid targets by the uplift multiplier?
Cautiously. The uplift suggests your platform-reported ROAS understates reality — so a 'losing' ad set on platform may actually be profitable. But before you change bids, validate with an incrementality test (Meta Conversion Lift, geo holdout). Two reasons: (1) the loss rate is a statistical estimate; your account-specific number can differ. (2) The algorithm uses reported events as signal; lifting bid targets without validating can scale low-quality conversions.
›How do I reduce iOS attribution loss?
Three priorities. (1) Implement Conversions API (CAPI) on Meta and Enhanced Conversions on Google — both pass first-party data server-side, which iOS doesn't break. Aim for 70%+ event coverage. (2) Pass hashed email + phone with every conversion event — these are the most reliable identifiers post-iOS. (3) For mobile apps, configure SKAdNetwork conversion values to track post-install events you actually care about (purchase, subscription start) instead of leaving defaults.
›Why is my iOS share important?
If iOS is 10% of your audience, the loss only applies to 10% of your conversions — total loss is small. If iOS is 60% (typical for US consumer brands), the loss compounds across most of your reported volume. iOS share also varies by category: premium brands skew iOS-heavy, value-oriented ecommerce skews Android-heavy, B2B SaaS sits in the middle.
›Does this affect Android ads too?
Less, but yes. Google's Privacy Sandbox is replacing third-party cookies in Chrome — the equivalent of iOS ATT for web. By 2026, the gap between iOS and Android attribution has narrowed. Server-side tracking (CAPI, Enhanced Conversions, Stripe revenue sync) is the durable solution; platform-specific pixel attribution will keep eroding regardless of OS.
Get iOS-adjusted ROAS automatically.
Floowzy joins your Stripe / Shopify revenue with Meta + Google spend and surfaces the actual cross-platform ROAS — not just the iOS-leaky platform-reported number.