Privacy Policy

Last updated: June 8, 2026

This Privacy Policy explains how the Caffeine Half-Life Calculator ("we", "us", "the site", available at lastcup.app) handles information when you use the site. We have written it to be plain and honest about what is — and is not — collected by a simple, free calculator tool.

What this site is

lastcup.app is a free caffeine half-life calculator. The calculations you run happen entirely in your own browser. We do not require you to create an account, and we do not ask for your name, address, or any personal identifying information to use the calculator.

Information the site itself collects

The calculator is client-side. The drinks, times, and settings you enter are processed in your browser to draw the graph and the result — they are not transmitted to or stored on our servers. We keep this data minimal on purpose:

• Local storage on your device. The site uses your browser's local storage to remember small preferences, such as your light/dark theme choice. If you choose to submit your email to our optional newsletter box, that email may also be stored locally in your browser. This information stays on your device and is not a server-side database of personal records.
• No accounts, no profiles. We do not build a personal profile of you, and we do not sell personal information.
• Server logs. Like virtually all websites, our hosting provider may automatically record standard technical request information (such as IP address, browser type, and the pages requested) for security and reliability. This is standard web-server logging, not a tracking program we operate.

Cookies

This site uses cookies and similar technologies (such as your browser's local storage). Cookies are small files placed on your device. We use them to remember your preferences and to support the advertising described below. Most browsers let you refuse or delete cookies through their settings; doing so may affect how some features remember your choices.

Third-party advertising and Google

This site is supported by advertising. To keep the calculator free, we display ads served by third-party vendors.

• Third-party vendors, including Google, use cookies to serve ads based on a user's prior visits to this website and other websites on the internet.
• Google's use of advertising cookies enables it and its partners to serve ads to you based on your visit to this site and/or other sites on the internet.
• Third-party vendors and ad networks may also use cookies or web beacons to collect information (such as your device's IP address and browsing activity) in the course of serving ads, in order to measure ad performance and show more relevant advertising.

How to opt out of personalized advertising

You can control or opt out of personalized advertising:

• Opt out of Google's use of advertising cookies by visiting Google Ads Settings.
• Opt out of personalized advertising from many participating vendors at www.aboutads.info/choices (Digital Advertising Alliance) and www.youronlinechoices.eu (for users in the EU).
• You can also manage cookies directly in your browser settings, or browse the site in a private/incognito window.

For more on how Google handles data when you use our partners' sites or apps, see Google's Privacy & Terms — How Google uses information from sites or apps that use our services.

Analytics

We may use privacy-respecting analytics to understand aggregate, non-identifying usage (for example, how many people visited a page). Any such analytics is used to improve the site, not to identify individual visitors.

Children's privacy

This site is intended for a general audience and is not directed at children under 13. We do not knowingly collect personal information from children.

Your choices

You can clear the site's stored preferences at any time by clearing your browser's cookies and local storage for lastcup.app. Because the calculator runs in your browser, doing this simply resets the tool to its defaults.

Changes to this policy

We may update this Privacy Policy from time to time. When we do, we will revise the "Last updated" date at the top of this page. Continued use of the site after a change means you accept the updated policy.

Contact

If you have questions about this Privacy Policy or how your information is handled, contact us at privacy@lastcup.app.

This calculator is provided for educational purposes only and is not medical advice. Consult a clinician for health decisions.