Privacy
Calculations run in your browser. Non-default inputs may appear in the page URL so you can reopen or share a calculation. If that URL is opened, its values are sent as part of the request to our hosting provider. Avoid sharing URLs containing sensitive values. We use GoatCounter for site visit statistics. Advertising on this site is delivered by Adsterra, a third-party ad network. Ad units appear on site pages. Adsterra and its partners may receive your IP address, the page URL and details of your device and browser, and may store or read cookies and similar identifiers to choose, cap and measure ads. Blocking third-party cookies in your browser stops that selection, though ads still appear. Adsterra’s privacy policy sets out what it collects and how to exercise your rights.
Last updated: 2026-10-22
Information we collect
You do not need an account or email address to use the calculators, and we do not send calculator fields to a calculation API. Changed values may be included in the URL; when a URL is opened, the hosting provider receives that request. Hosting request logs can include the full URL if logging is enabled. GoatCounter receives page-view events using this page’s canonical path, plus referrer and technical visit data.
Cookies and local storage
The site saves your light or dark theme choice in localStorage; calculator inputs are not saved there. Changed values can remain in the page URL and your browser history until you remove or replace them. The site saves the last four calculator identifiers in localStorage for the recently used list. It does not save their input values. You can clear this list on the homepage. If you change the appearance, your light or dark preference is saved in this browser's local storage. Calculator inputs are never saved.
Analytics and advertising
We use GoatCounter to measure visits. In this site’s setup, the analytics path uses the canonical page URL, which excludes calculator query values. GoatCounter documents aggregate visit statistics and temporary processing of network information to distinguish repeat visits; see its privacy policy for details. Advertising on this site is delivered by Adsterra, a third-party ad network. Ad units appear on site pages. Adsterra and its partners may receive your IP address, the page URL and details of your device and browser, and may store or read cookies and similar identifiers to choose, cap and measure ads. Blocking third-party cookies in your browser stops that selection, though ads still appear. Adsterra’s privacy policy sets out what it collects and how to exercise your rights. Homepage events count search use, empty results, entry types and time-to-first-tool bands. They exclude search text and calculator inputs.
Third-party links
Some pages link to other websites. We do not control them and are not responsible for their privacy practices; please read the policy of any site you visit through a link.
Your rights (GDPR / CCPA)
If you have a question or request about information associated with a visit, contact us at the address below. We will review it under the laws that apply and explain whether the relevant information is held by us, our hosting provider, or GoatCounter / Google.
Children’s privacy
This site is not directed at children under 13, and its calculators are general-purpose tools. Do not enter a child’s or anyone else’s identifying or sensitive information into a calculator or include it in a URL you share. Hosting and analytics may process visit information as described above.
Data retention and security
Calculator fields are processed in your browser rather than sent to a calculation API. Changed values may be placed in the URL and remain in browser history; reopening that URL sends it to the hosting provider, whose request logs may include the URL if logging is enabled. GoatCounter handles analytics data under its own retention policy. The site does not save calculator inputs in localStorage.
Changes to this policy
We may update this page as the site changes. The date shown at the top reflects the latest revision, and material changes will be reflected here before they take effect.
Contact
Questions about this policy or about how the site works: hqzhon@gmail.com