Free tool Cookie consent loss calculator: what your analytics no longer sees
When a cookie banner asks for consent, everyone who says no — or ignores it — disappears from analytics that need consent. Enter your traffic, the share of visitors who see the banner and your own consent rate to see how many visitors, conversions and how much revenue go missing, and how much that bends your conversion rate.
- Missing visitors and revenue
- Your consent rate, not an average
- Runs locally
How much traffic the banner hides
Start from your real total (server logs, orders, a cookieless tool) or from the number your consent-based analytics shows. The consent rate comes from your banner or CMP dashboard.
Pick “visitors in my analytics” if you only have the consent-based number; the calculator works back to the total.
Everyone who visited in the period, counted without consent — server logs with bots removed, or a cookieless tool.
What your consent-based tool reports for the period, e.g. users in GA4 without modelling.
Share of traffic shown a consent banner. 100 if everyone sees it; your EU / UK share if only they do.
Of those who see the banner, the share who allow analytics. Ignoring the banner counts as no.
Optional. Orders, sign-ups or leads ÷ visitors.
Optional. Average order value or what a lead is worth.
Visitors your analytics cannot see
9,000
Total × share who saw the banner × (1 − consent rate).
Share these inputs: the values go after the # in the link, so they never reach a server.
https://tapcub.com/tools/cookie-consent-loss-calculator
Version v1.0Updated Update history
What the missing numbers mean
The banner does not lose you customers; it loses you the record of them. Read each figure with that in mind.
Visitors your analytics cannot see
9,000 of 50,000 visitors in the example: 40% saw the banner and 45% of those did not allow analytics. They still browse and buy; your reports just never hear about them.
Scale-up factor
1.22× means real traffic is about 22% above what consent-based analytics shows. The factor is only as good as your consent rate, and it shifts when the banner design or the visitor mix changes.
Conversions and revenue without a source
180 conversions and $14,400 have no channel, campaign or landing page attached. Channel ROI looks worse than it is, and the channels whose visitors decline more often look worse still.
Inflated conversion rate
Divide all 1,000 backend orders by the 41,000 visitors analytics saw and you get 2.44% instead of 2.00%. Compare like with like: tracked conversions ÷ tracked visitors, or orders ÷ all visitors.
This page does not supply an industry consent rate. Consent rates depend heavily on how the banner is designed and who your visitors are, so use the number your own banner reports.
Three numbers from your own setup
Everything here comes from tools you already have.
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1
Get the consent rate
From your banner or CMP dashboard: visitors who allowed analytics ÷ visitors shown the banner. Make sure ignoring the banner counts as no.
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2
Decide who sees the banner
If the banner only shows in the EU and UK, use their share of your traffic. If it shows to everyone, enter 100.
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3
Add traffic and conversions
Enter all visitors (server logs without bots, or a cookieless tool) or the consented number your analytics shows; then your conversion rate and value per conversion.
Consent loss formula
Only visitors who see the banner and do not consent drop out of consent-based analytics. Everything else follows from that share.
- Missing share = share who see the banner × (1 − consent rate)
- Working back from analytics: total = visitors in analytics ÷ (1 − missing share)
- Missing conversions assume non-consenters convert at the same rate — the biggest assumption on this page
- GA4 behavioural modelling can estimate some of the gap only above Google's data thresholds (see the FAQ)
Missing share
banner share × (1 − consent rate)
40% × (1 − 55%) = 18%
Missing visitors
total visitors × missing share
50,000 × 18% = 9,000
Scale-up factor
1 ÷ (1 − missing share)
1 ÷ 82% = 1.22×
Missing conversions
missing visitors × conversion rate
9,000 × 2% = 180
Inflated conversion rate
conversion rate ÷ (1 − missing share)
2% ÷ 82% = 2.44%
Same traffic, different consent rates
50,000 visitors a month, 40% of them from the EU and UK where the banner shows, 2% conversion, $80 per order.
| Consent rate | Missing share | Missing visitors | Revenue without a source | Scale-up factor |
|---|---|---|---|---|
| 30% | 28.0% | 14,000 | $22,400 | 1.39× |
| 55% | 18.0% | 9,000 | $14,400 | 1.22× |
| 70% | 12.0% | 6,000 | $9,600 | 1.14× |
| 90% | 4.0% | 2,000 | $3,200 | 1.04× |
A banner redesign that moves the consent rate changes your reported traffic even if real traffic did not move. Annotate the date in your reports.
Where consent maths goes wrong
Four ways to misread the gap.
Using somebody else's consent rate
Rates quoted in blog posts come from other sites, banners and audiences. Your own banner logs are the only number that fits.
Leaving out people who ignore the banner
A visitor who never clicks has not consented. Rates computed only from people who clicked look far higher than reality.
Reading a banner change as a traffic change
A new banner design or a new region rule moves reported visitors overnight. Mark the date before anyone celebrates or panics.
Mixing tracked and untracked numbers
Backend orders ÷ tracked visitors inflates conversion rate. Keep numerator and denominator from the same source.
Analytics that keeps counting without a cookie
TapCub analytics writes nothing to the browser by default, so the device-storage part of the consent question does not come from the script. Whether processing still needs consent depends on your setup and local law.
No analytics cookie or local storage
Visitors are told apart on the server with a keyed hash of the site, a salt, the IP address and the browser type. The IP itself is never stored.
Learn moreConsent rules by region
The compliance centre decides where consent is required. Where it is required and not given, the hit is kept at the anonymous-aggregate tier — daily salt, no persistent ID — instead of being identified.
Learn moreHumans and bots on separate rows
Crawler traffic is counted on its own, so the “total visitors” you compare against is not padded with bots.
Learn moreCookie consent rate FAQ
Still have a question?
Chat with the team behind TapCub — we usually reply within a few hours on business days.
How do I calculate my cookie consent rate?
Consent rate = visitors who allowed analytics ÷ visitors shown the banner. Most banner tools and CMPs report it. Count visitors who ignored or closed the banner without choosing as not consented — under the GDPR consent has to be an affirmative act.
What is a typical cookie consent rate?
There is no single figure worth planning with. In a field study on a German website with more than 80,000 visitors, Utz et al. (ACM CCS 2019) found that a simple accept / decline choice got more acceptance than per-category or per-vendor choices, and that nudging had a large effect. Your design and audience decide your rate, so use your own logs.
Can GA4 Consent Mode fill in the missing users?
Partly, and only as an estimate. Google's behavioural modelling needs the property to collect at least 1,000 events a day with analytics_storage denied for at least 7 days, and at least 1,000 daily users with it granted for 7 of the previous 28 days; even then Google may decide the data is not enough. In basic mode nothing is sent before consent, so there is nothing to model from.
Do visitors who decline convert like everyone else?
Nobody knows for your site until you check. Compare orders in your backend with conversions in analytics for the same period: if the gap is bigger than the missing share, decliners convert more; if smaller, less.
Why does my conversion rate look higher after adding a banner?
If conversions come from your backend (every order) but visitors come from consent-based analytics (consented only), the denominator shrank and the numerator did not. The calculator shows the inflated figure next to the real one.
Does cookieless analytics need a consent banner?
It depends on what the tool does and where your visitors are; this is not legal advice. A script that stores nothing on the device avoids the cookie part of the rule, but processing personal data can still need a legal basis or consent. TapCub lets you require consent by region in the compliance centre.
Where do I get the total number of visitors?
From something that does not depend on consent: server or CDN logs with bots filtered out, or a cookieless analytics tool. Raw logs include crawlers, so filter them first or your missing share comes out too high.
Update history
New features, fixes and data refreshes for this tool, newest first.
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· v1.0
LaunchedFirst release.
Missing something or found an error? Tell us — requests that come up often go into the next update. All tool updates
Shrink the gap, or measure without it
Make the banner honest and easy to answer, set up Consent Mode correctly, or count visits in a way that does not rely on a cookie.