Privacy Policy

The short version

CaffCalc is a static website. There is no account system, no login, and no database of users. The only visitor data we see is anonymous, aggregated traffic reporting from Google Analytics, described in full below.

Last updated: September 12, 2026

Calculator inputs stay in your browser

When you use the caffeine calculator, you may enter or select a body weight, an age group, a gender, pregnancy or breastfeeding status, a sensitivity level and the drinks you consume. All of this is handled by JavaScript running on your own device. No part of it is sent to CaffCalc or to any third party.

So that you do not have to re-enter your details on every visit, the calculator saves your preferences in your browser's local storage. Local storage is a private area of your own browser; it is not a cookie, it is not transmitted with web requests, and we cannot read it. The site stores three items:

• caffeineCalculatorPreferences — your age group, gender, weight and weight unit, pregnancy and breastfeeding status, sensitivity level and volume unit.
• lastSearch — the most recent term you typed into the site search box.
• scrollToElementId — a temporary marker used to scroll you to the right section after navigating between pages. It is deleted immediately after use.

You can erase all three at any time by clearing site data for caffcalc.com in your browser settings. Doing so simply resets the calculator to its defaults.

The list of drinks and their caffeine values is loaded from a static file hosted on this site. Requesting it tells us nothing about you beyond an ordinary page request.

Analytics

We use Google Analytics 4 to understand which pages people find useful and where visitors come from. On mobile devices the analytics script is deliberately delayed until after the page has finished loading, so that it does not slow the site down.

Google Analytics collects:

• Pages viewed and the order you viewed them in
• Approximate location, derived from your IP address and generalised to city or region level
• Device type, screen size, operating system and browser
• The referring site or search engine that brought you here

This data is aggregated and is not used to identify you personally. We do not upload any calculator inputs to Google Analytics, and we do not use Google Signals, advertising personalisation or cross-device tracking features.

Cookies

CaffCalc does not set any cookies of its own. The only cookies placed on your device come from Google Analytics — typically _ga and a container-specific _ga_* cookie, which distinguish one browser from another so that repeat visits are not counted twice.

You can block or delete these through your browser's cookie settings, by using Google's official Analytics opt-out browser add-on, or by browsing in a private window. The calculator works normally with all cookies blocked.

Third parties

A handful of external services are involved in delivering this site. Because your browser fetches files directly from them, each necessarily receives your IP address and user-agent string as part of that request:

• Google Analytics — traffic measurement, as described above.
• Google Fonts — serves the two typefaces used across the site.
• jsDelivr and unpkg — content delivery networks that serve the site's styling framework and icon set.
• Our hosting provider, which keeps standard server logs of requests for security and reliability purposes.

Looking ahead: CaffCalc does not currently carry advertising. If advertising partners are added in future, this policy will be updated before any advertising code is placed on the site, and it will name the partners and describe what they collect.

Your choices

• Clear your stored preferences — clear site data for caffcalc.com in your browser.
• Opt out of analytics — use the Google opt-out add-on linked above, block third-party scripts, or enable your browser's tracking protection.
• Use the calculator with JavaScript restrictions — the calculator requires JavaScript to run, but it does not require cookies or analytics to be enabled.

Because we do not hold personal data about you, there is no account to delete and no personal record for us to export. If you believe we hold something about you regardless, contact us and we will investigate.

Children

CaffCalc is intended for adults. We do not knowingly collect personal information from children, and the calculator itself is built to be conservative about caffeine for anyone under 18 — see our Terms of Use.