LayoutMath does not ask you to sign up, does not set cookies and does not send the numbers you type to any server. The calculators run in your browser.
What is stored on your device
When you switch units or currency, the page saves that choice in your browser's local storage under the key bh-prefs, so the next page opens in the same units. It contains only the unit system and the currency symbol. If you use the sun and moon button in the header, your choice of light or dark is saved the same way, under the key bh-theme, so the next page opens in the same theme. Clearing your site data removes both.
Analytics
This site does not run analytics scripts.
Hosting
The site is served by Cloudflare. Like any web host, it processes your request, including your IP address, to deliver the page, and may keep standard server logs.
If you write to hello@layoutmath.com, we use your address only to reply.