Privacy policy
Updated July 2026
The short version
We don't run ads and we don't sell your data. The calculators run entirely in your browser — the numbers you type are not sent to us or stored on a server. We use Google Analytics to see which pages are useful, and that's the extent of it.
What we collect
- Standard server logs. Like any website, our host records requests (IP address, page, timestamp, browser type) for security and reliability. These are kept briefly and not used to profile you.
- Google Analytics 4. We use GA4 to count visits and see which pages and tools people actually use: pages viewed, rough location (city level), device and browser type, and how you arrived (search, link, direct). GA4 does not log or store your IP address. We don't use it for advertising, and we have not enabled ads personalization. Details: Google's privacy policy.
- What you send us. If you email a correction or question, we keep that message to reply.
What we don't do
- No advertising networks and no ad-targeting cookies.
- No selling, renting, or sharing of personal data.
- No account required; the tools work without signing in.
Cookies & local storage
Google Analytics sets its measurement cookies (_ga and _ga_*) to tell returning
browsers apart in aggregate statistics. That's the only cookie use on this site — there are no advertising
cookies. The numbers you type into the calculators never leave the page.
Your choices
You can block or delete analytics cookies in your browser, use a content blocker, or install Google's Analytics opt-out add-on — every tool on this site works exactly the same without analytics. For any privacy question, or to ask what (if anything) we hold about a message you sent, use the contact page.
This policy may be updated; the date above reflects the current version.