Privacy

Last updated 5 August 2026.

The short version: this site does not collect anything about you personally. There are no accounts, no advertising and nothing you type is transmitted anywhere. Google Analytics measures traffic in aggregate, covered in full below.

Your calculations stay in your browser

Every calculator on this site runs entirely as JavaScript on your own device. The masses, molar masses and percentages you enter are used to compute a result on screen and are never sent to a server, because there is no application server to send them to. The site is static files.

Closing the tab discards the values. Nothing is written to a database and nothing is retained.

What is stored on your device

This site itself writes nothing to local storage and sets no cookies of its own, so nothing here carries over to your next visit. Google Analytics is the exception: it sets its own cookies to distinguish repeat visits, described in the Third parties section below. Clearing your browser storage removes those too.

The one URL-based feature is a deep link: adding query parameters to the calculator's address (for example ?a=4&t=5) preloads those values when the page opens. That only happens if you or someone else builds or bookmarks a link like that, and it never happens automatically as you type.

Hosting and server logs

The site is served as static files by a hosting provider. Like any web host, it processes standard request information such as your IP address, the page requested and your browser's user agent, for the purpose of delivering the page and protecting against abuse. That processing is the host's, not this site's, and no additional logging is configured on top of it.

Third parties

Google Analytics runs on every page to measure traffic: which pages get visited, roughly how, and from where, in aggregate. It sets its own cookies and can read your IP address and browser details to do this, under Google's own privacy policy. This site does not receive your name, email or anything you type into a calculator, because that data never leaves your browser in the first place. There is nothing else third-party on the pages: no advertising tags, no social widgets and no embedded videos or iframes. No fonts are fetched from a third-party service either, since the one font used is served from this domain.

Children

The site is a general-audience reference tool and is commonly used by students. Since no personal information is collected from anyone, no information is collected from children either.

Changes and contact

If this policy changes, the date at the top of the page changes with it. Questions about privacy can go to contact@percentyieldcalculator.org, or through the contact page. See also the terms of use for what the site itself can be relied on for.