Your numbers stay yours
Your calculations never leave your browser. Here is the plain-English version of what we do and do not collect, including what our ad network and analytics tools see.
Calculations run in your browser
Every calculator computes locally on your device. The values you type, your weight, your salary, your measurements, are never transmitted to our servers, because there is no server doing the math.
No accounts
You don't need to sign up to use anything here. We don't ask for your name or email to run a calculator, and we ourselves do not build a personal profile of you. When you copy a result link, the inputs are encoded in that URL so you can share or revisit them; that link is only created when you ask for it.
Advertising
This site is free because it shows ads. We use Adsterra, a third-party ad network, to serve the display ads you see on calculator pages. To do this, Adsterra and its advertising partners may set their own cookies or similar identifiers in your browser and collect data such as your IP address, device and browser information, and how you interact with ads, in order to show ads and measure their performance. This processing is carried out by Adsterra as a third party; we do not receive or store that advertising data ourselves.
You can review Adsterra's practices and opt-out options in the Adsterra Privacy Policy. You can also limit interest-based advertising through industry tools such as YourAdChoices (US) and Your Online Choices (EU), and through your browser's cookie and tracking controls.
Your choices (GDPR / CCPA)
Depending on where you live, you may have the right to access, correct, or delete personal data, to object to or restrict certain processing, and to opt out of the sale or sharing of personal information for targeted advertising. Because the advertising data is collected by Adsterra, and the session-analytics data by Microsoft, rather than by us, the most direct controls are the ad-network, Microsoft and browser opt-outs linked on this page. For anything else, contact us and we will help or point you to the right place.
Analytics
We use two analytics tools, and they collect different amounts of data.
Vercel Web Analytics counts page views. It is cookieless and aggregate: it tells us which calculators are visited and how often, not who visited them.
Microsoft Clarity goes further. It records how people interact with a page, including session replays (pointer movement, clicks, scrolling, and which elements you interacted with) and aggregated heatmaps, and it stores identifiers in your browser to do so. This is product research: we use it to find layouts and controls that confuse people. The processing is carried out by Microsoft as a third party under the Microsoft Privacy Statement, and Microsoft may use the data in line with that statement.
Clarity masks the text typed into input fields by default, so the numbers you enter (a
weight, a salary, a lab value) are not intended to be captured in a recording. Separately,
and regardless of any analytics setting, the calculations themselves run entirely in your
browser, so the values you enter are never transmitted to our servers. You can opt out of Clarity, and of Microsoft advertising and analytics generally,
through the
Microsoft opt-out page, or by blocking clarity.ms in your browser or an extension. Browser "do not
track" and cookie controls also apply.
Embedded calculators
Our embeddable widgets load only the calculator and an attribution link, and set no tracking cookies of our own on the sites that host them.
Contact
Questions about privacy or a data request? Reach us through our contact page. See also our Terms of Use.