The short version: no tracking cookies, no data sold, and the calculators run entirely in your browser.
Analytics
To see which pages are read, the site uses a self-hosted, privacy-friendly analytics tool rather than handing your visit to a third party. It sets no cookies and does not track you across other sites; it records a page view with non-identifying details such as the page, the referring site and a broad country, and does not store your full IP address. Because nothing identifies you and no cookie is set, no consent banner is needed.
The calculators
Everything you type into the calculators stays in your browser. Nothing is sent to a server or saved anywhere.
Fonts and advertising
Pages load a typeface from Google Fonts, so your browser fetches font files from Google. The site may carry advertising in future to cover its costs; if it does, this page will be updated to describe exactly what that involves before any advertising appears.