Privacy & disclaimer

Last updated: 2026-10-02

What this site collects

This site uses Cloudflare Web Analytics to count visits (pages viewed, country, referring site, device type). It does not use cookies and does not track individual visitors across sites. There is no advertising.

The visitor count shown at the bottom of each page is counted by this site itself, once per browser per day. To do that, the date of your last visit is kept in your browser (local storage, not a cookie). Only the number of visits per day is saved on the server; nothing that identifies you, such as your IP address, is stored.

The tools run entirely in your browser; the values you type are not sent anywhere and are not saved.

The site is hosted on Cloudflare, which may keep standard access logs (such as IP addresses) to operate and protect the service. Fonts are loaded from Google Fonts, which receives a normal web request when a page loads.

Comments

When you post a comment, the name (optional), the text and the time are saved and shown publicly on the page. Your IP address and email address are not saved. Before a comment is accepted, Cloudflare Turnstile checks that it was sent by a person; Cloudflare processes the data needed for that check. Please don't include personal information. The site owner may delete comments without notice. When a comment is posted, its content is also sent to the owner by email through Resend, an email delivery service.

Contact form

Messages sent from the contact form (name, email address if given, and message) are delivered to the owner by email through Resend. They are not published or stored on this site. Your email address is used only to reply to you.

Disclaimer

The tools and notes here are provided as-is, for reference. Results are estimates. For medical-equipment tools in particular, actual gas consumption depends on the device, settings, circuit, leaks and the patient. Always check the manufacturer's instructions and decide what you need yourself. The author accepts no responsibility for any outcome of using this site.

Support (Ko-fi)

The "Support on Ko-fi" buttons link to an external site, Ko-fi. Tips are processed by Ko-fi and its payment provider (Stripe); this site never receives your card details. Please see Ko-fi's own privacy policy for how they handle your information.

Changes

This page may be updated if the site starts using new services. The date above shows the latest version.