Privacy Policy

Last updated: August 8, 2026 · applies to btengineering.net

The short version

This site has no accounts, no logins, and no contact forms. The calculators run entirely in your browser — the numbers you type never leave your device. The only third-party data collection on this site comes from advertising (Google AdSense) once ads are live.

What we collect

Nothing directly. We don't operate a backend, don't set our own tracking cookies, and don't collect names, emails, or calculator inputs. If you email us, we see what you send and use it only to reply.

Advertising (Google AdSense)

We use Google AdSense to serve ads, which is how a free site covers its hosting and domain costs. Google and its partners may use cookies and similar technologies (such as web beacons and device identifiers) to serve ads based on your visits to this and other websites, measure ad performance, and prevent fraud.

• Google's use of advertising cookies enables it and its partners to serve ads based on your visits to this site and other sites on the Internet.
• You can opt out of personalized advertising in Google's My Ad Center, or opt out of many third-party vendors' cookies at aboutads.info/choices.
• Details on how Google uses data from sites that use its services: policies.google.com/technologies/partner-sites.

Your choices in the EEA, UK, and Switzerland (GDPR)

If you visit from the European Economic Area, the United Kingdom, or Switzerland, you will see a consent message (Google's certified consent management platform) before any advertising cookies are set. You can decline, consent, or change your choice later; declining limits ads to non-personalized ones. The legal bases for ad-related processing are your consent (personalized ads) and legitimate interest (basic ad delivery, fraud prevention, and measurement, as described in the consent message).

You also have the rights of access, rectification, erasure, restriction, portability, and objection over personal data processed about you. Because this site itself stores no personal data, these requests generally concern Google's processing — the links above are the fastest route, but you can also contact us and we'll help direct the request.

California residents (CCPA/CPRA)

We don't sell personal information ourselves and don't collect it in the first place. Third-party advertising cookies may constitute "sharing" for cross-context behavioral advertising under the CPRA; you can opt out via the ad-settings links above or your browser's Global Privacy Control signal, which Google honors.

Local storage

Calculators may use your browser's local storage to remember preferences (like units or your last-used material) on your own device. This data never leaves your browser and you can clear it any time through your browser settings.

Hosting logs

Our hosting provider (Cloudflare) processes standard server logs — IP address, user agent, pages requested — to deliver the site and mitigate abuse, per Cloudflare's privacy policy. We don't use these logs to identify visitors.

Children

This site is a machining reference intended for a general and professional audience and is not directed at children under 13. We do not knowingly collect personal information from children.

Changes

If this policy changes, the date at the top changes with it. Material changes (like adding a new third-party service) will be noted here.

Contact

Privacy questions: see the contact page.