Privacy Policy

What we collect

Calculator inputs: nothing. Every calculation on thecalclibrary.com runs entirely in your browser using JavaScript. The numbers you type — your income, weight, dates, grades — are never transmitted to our servers, because there is no server-side calculation to transmit them to.

Site preferences. Your light or dark theme choice is stored in your browser's local storage so the site remembers it next visit. It stays on your device and is never transmitted.

Standard server logs. Like nearly every website, our hosting provider records basic request information — IP address, browser type, referring page, and the time of the request. This is used to keep the site running and to detect abuse. These logs are retained for a limited period and are not linked to you as an individual.

Usage analytics. We use Google Analytics 4 to understand which calculators people use and how they find the site, so we know what to build next. It records the pages you visit, roughly where in the world you are, the type of device and browser you use, and which site referred you. It does not receive anything you type into a calculator.

Cookies

We set no advertising cookies and run no ad network. Google Analytics does set its own first-party cookies to tell repeat visits from new ones. You can block these with any standard browser content blocker, by enabling “Do Not Track”, or with Google's own opt-out browser add-on. Nothing on this site stops working if you do.

Third-party services

The site is hosted on Vercel, which processes requests to serve pages to you and keeps its own server logs under its privacy policy. Fonts are served from our own domain rather than a third-party font CDN, so no request data is shared for fonts.

Google Analytics is provided by Google, and data collected through it is handled under Google's privacy policy. IP addresses are anonymised by default in Google Analytics 4.

Children

This site is not directed at children under 13 and we do not knowingly collect personal information from them.

Your rights

Because we do not build user profiles or store personal data tied to you, there is generally nothing for us to access, correct, or delete. If you have contacted us by email, you can ask us to delete that correspondence at any time. Depending on where you live, you may have rights under the GDPR, UK GDPR, or CCPA — write to us and we will honour them.

Changes to this policy

If this policy changes materially, the updated date at the top of this page will change and the substance of the change will be described here.

Contact

Questions about privacy can go to our contact page or directly to hello@thecalclibrary.com.