Cookie banner traffic loss calculator
Work out how many visitors your consent-gated analytics never sees, and what that gap is worth. Free, no account, and every number stays in your browser.
- Free, no account
- Runs in your browser
- Nothing is sent to us
Your numbers
Total visitors a month, before any consent filtering.
From your consent tool. Reported rates vary widely by region, industry and banner design, so use your own number rather than a published average.
Optional. Revenue per visitor, if you track it, to put the gap in money.
Enter your monthly visitors and the share who decline the banner. Everything is calculated in your browser.
What this calculates
If your analytics only runs after someone accepts a banner, then everyone who declines is missing from every number you have. This works out how many people that is, over a month and over a year, and optionally what the gap is worth in revenue.
The arithmetic is simple. The point is not the formula, it is seeing the number written down.
Why there is no default decline rate
Most calculators like this ship with an “industry average” pre-filled. This one deliberately does not.
Published consent rates disagree wildly, because they measure different things. Rates vary by country, by sector, by how the banner is designed, by whether declining takes one click or four, and by whether the study was run by a company selling consent optimisation. Picking one number and presenting it as typical would be exactly the kind of unsourced claim this company argues against elsewhere.
Your consent platform already knows your real rate. Use that.
What the gap actually does to your decisions
The missing visitors are not randomly distributed, which is the part that does real damage.
People who decline tracking skew toward the more privacy-aware, which correlates with technical audiences, certain regions, and certain browsers. So the sample you keep is not a smaller version of your traffic, it is a biased smaller version. Every ratio you compute from it inherits that bias:
- Channel mix looks wrong. If one channel brings more privacy-conscious visitors, it appears to underperform.
- Conversion rates look better than they are. The denominator lost visitors, so the rate rises without anything improving.
- Geographic reporting is skewed. Consent rates differ sharply by country, so your EU traffic is systematically undercounted against markets with no banner.
- A/B tests get slower and noisier. You are only measuring the consenting half.
None of this shows up as an error. The dashboard renders confidently and is simply wrong.
Consent mode and modelling do not close it
The usual answer is behavioural modelling: estimate what the unconsented visitors probably did, based on the ones who consented.
That is a projection built on the assumption that the two groups behave the same way. If they did, consent choice would be random, and it is not. Modelling makes the reported gap smaller without making the measurement gap smaller. It is a reasonable coping mechanism, not a fix.
The other way to close it
There is a second option, and it is the one nobody selling consent optimisation will mention: stop needing consent.
If your analytics sets nothing on the device and retains no personal data, no visitor is excluded, because none of them were ever asked. The number you see is the number of people who came. sonex works this way, which is why the gap this calculator measures is zero for sites that use it.
Not sure whether your banner is required at all? Check whether you actually need one before optimising it.
Frequently asked.
- Why does a consent banner reduce my analytics numbers?
- Cookie-based analytics cannot run until the visitor accepts. Everyone who declines, ignores the banner, or leaves before answering it is never counted. Your dashboard reports the people who consented, not the people who visited, and the difference is invisible from inside the dashboard.
- What is a typical consent decline rate?
- There is no single credible figure. Published rates vary enormously by region, industry, banner design and how aggressively the banner nudges. That is why this calculator has no default value and asks for the number from your own consent tool instead of inventing an average.
- Where do I find my own decline rate?
- Most consent management platforms report acceptance or opt-in rate in their dashboard. Your decline rate is a hundred minus that. If your platform only reports accepted counts, divide accepted by total banner impressions.
- Does consent mode or modelling fix the gap?
- Not really. Modelled conversions estimate what unconsented visitors probably did, using data from consented ones. That is a projection, not a measurement, and it inherits whatever bias separates the two groups. It narrows the reported gap without narrowing the actual one.
- Do cookieless analytics tools count everyone?
- They count everyone who loads the page and is not blocked by an ad blocker or a browser privacy feature. Because they need no consent, no visitor is excluded for declining, so the count is usually meaningfully higher than a consent-gated tool reports for the same site.