Privacy Policy

Last updated: October 28, 2026

1. Summary

We collect as little as we can. We do not sell your data. This page lists what we collect.

2. What we collect

  • Account details. The name and email address you give when you register, and the sign-in details needed to keep your account (a hashed password, or the profile your Google or GitHub account shares if you sign in with one). We also store the interface language and any referral code attached to the account.
  • Where you signed up from. If you register after using a calculator, we store that calculator's page name (for example conduit-fill-calculator) with your account.
  • Funnel events. When you finish a calculation, click a call-to-action or sign up, we record the event name, the calculator it happened on, your user ID if you are signed in, and the time. We do not record what you typed into a calculator.
  • Rate-limiting data. To stop abuse we keep a keyed hash (HMAC) of your IP address with a counter, for a short time (two days at most). The raw IP address is not stored in our database and is not saved with funnel events.
  • Cloudflare Web Analytics. We use it to count visits and see which pages are used. It does not use cookies.
  • Google Analytics 4. We use Google Analytics 4 to count page views and three events: finishing a calculation, clicking a call-to-action, and signing up. The events carry the page name of the calculator involved (for a sign-up, the calculator you signed up from), and we send no names, email addresses or user IDs. Page addresses are sent without their query strings. Google also receives standard technical data from your browser, such as your IP address, device and browser details. Google acts as our processor and sets the cookies _ga and _ga_<id> in your browser. We have turned off Google signals and ad personalization. For visitors in the EEA, the UK and Switzerland, analytics storage is denied by default. You can opt out with the Google Analytics opt-out browser add-on.

Our hosting provider, Cloudflare, also processes standard request data (such as your IP address) to deliver the site and keep it secure.

3. How long we keep it

Funnel events are deleted automatically after about 13 months. Rate-limiting hashes are deleted automatically after about two days. Account details are kept while your account exists. We have not set a fixed retention period for anything else, and we do not promise automatic deletion of it.

4. How we use it

To run the site, sign you in, understand which calculators are useful, keep the site secure, and email you about your account. We do not use it for advertising.

5. We do not sell data

We do not sell or rent your personal information. We share it only with service providers who run the site for us (for example hosting and email delivery), or when the law requires it.

6. Cookies

We use a sign-in cookie if you log in. See the Cookie Policy.

7. Your choices

You can ask us to see or correct your account data by writing to the contact address shown on the site. You can also ask us to delete your account; we will review the request and tell you what was removed.

8. Children

The site is for working professionals and is not directed to children under 13.

9. Changes

If we change this policy we will update the date at the top.