Privacy Policy

CalcLab (the "site") takes your privacy seriously and complies with applicable privacy laws. This policy explains what information the site handles and how.

1. What you type into a calculator — we do not collect it

Every calculator on this site runs entirely inside your browser. The site does not collect or store the values you enter, and it does not send them anywhere in order to do the arithmetic. The address bar does not change as you type. Your figures live inside the browser only while the page is open, and they are gone once you close it or reload.

There is exactly one way a value leaves: pressing "Copy result link" yourself. The link that button builds carries the values after the hash mark (#) — for example …/en-us/baby-percentile/#h=75.5&w=9.4. The URL standard reserves everything after the # for the browser itself, so it is never included in the request sent to a server (RFC 3986 §3.5). Whoever opens that link, the values do not reach this site's access logs or its hosting provider (section 3).

What the link does do is show the values to the person who receives it — reproducing your result is the point of it. If you entered a salary or a child's measurements, just be deliberate about who you send it to.

When you arrive through such a link, the page reads the values into the input fields and then clears them from the address bar right away — so they do not linger in a screen share or a screenshot, and the advertising and analytics scripts on the page cannot read them.

Until 16 August 2026 the values appeared in the address bar (?h=75.5) the moment you typed them, and opening such an address sent them along with the request. Links made back then still work — the page reads them, calculates, and clears the address just the same.

2. Accounts and personal information

The site has no sign-up feature. We do not directly collect personal information such as your name, email address, or phone number.

3. Access logs

The hosting provider this site uses may keep standard server logs — including IP address, access time, and browser information — as part of normal service operation and security. This information is used only for aggregate statistics and troubleshooting.

4. External price and exchange-rate data

Metal prices and exchange rates are fetched in advance, at the moment the pages are built, and written straight into the page. The site is rebuilt once a day and the figures are refreshed then. That means your browser does not contact any external price server when you open a page, and your IP address is never passed on to a data provider. The reference time shown next to a figure is the moment that figure was fetched, not the moment you loaded the page. Where you would rather work from a number you have checked yourself, the gold calculator takes a dealer's price typed in by hand.

5. Cookies and advertising

The site may display ads (for example, Google AdSense) to support its operation. Third-party ad vendors, including Google, may use cookies to show ads based on your prior visits. The ad script sends the page address along with its request, and what you type into a calculator is not part of that address (section 1). If you prefer not to see personalized ads, you can opt out in Google Ads Settings.

6. Visitor statistics

To see which calculators actually get used, the site runs Cloudflare Web Analytics. A short measurement script sits on every page and reports to Cloudflare when the page loads. What Cloudflare records is the domain and path of the page, the page you arrived from (the referrer), your browser, operating system and device type, the country you are in, and page load timings. Cloudflare states that the product uses no client-side state such as cookies or localStorage and does not identify individual visitors or follow them from one site to another, and that it does not log query strings, precisely so that potentially sensitive values sitting in an address are not collected. The details are in the Cloudflare Web Analytics documentation.

7. Changes to this policy

If anything in this policy is added, removed, or changed, we will announce it on this page.

8. Contact

Questions about privacy: calculab.admin@gmail.com

Effective date: August 4, 2026