Privacy

This site is built so that visiting it produces as little data as possible. No analytics, no tracking, no consent prompt, no embedded third-party content. Fonts, scripts and images are served from the same server as the page itself — loading a page opens no connection to any third party at all.

The German version of this page is the legally binding one.

Controller

HelpfulCalculator – Sören Striewski c/o Autorenglück #35312 Albert-Einstein-Straße 47 02977 Hoyerswerda Germany

Email: contact@helpfulcalculator.com

Server log files

When you request a page, your browser transmits technically necessary data that the host records in log files: IP address, date and time, the address requested, the amount of data transferred, browser type and operating system, and the previously visited page if your browser sends it.

The legal basis is Art. 6(1)(f) GDPR. The legitimate interest is the technically sound operation of the site and the defence against attacks. This data is not combined with other sources and is not evaluated to analyse user behaviour.

Hosting

This site is served on Cloudflare Pages by Cloudflare, Inc., 101 Townsend Street, San Francisco, CA 94107, USA. When you request a page, Cloudflare processes the server log files described in the section above in order to deliver the site and to defend against attacks.

Cloudflare is a processor under Art. 28 GDPR. The processing is governed by Cloudflare’s data processing addendum, which incorporates the European Commission’s standard contractual clauses.

Data may be transferred to the United States. Cloudflare, Inc. is certified under the EU-US Data Privacy Framework; the transfer relies on that certification and, in addition, on the standard contractual clauses.

Log files are retained for Cloudflare’s default retention period and deleted afterwards.

Cookies

This site sets no cookies.

Local storage

The calculator can remember two things in your browser’s local storage:

Neither value is transmitted to us or to anyone else; both stay in your browser, and neither contains an identifier that could recognise a device or a person.

hc-unit-system is created only when you use the unit switch yourself. The legal basis is section 25(2)(2) TTDSG: the storage is strictly necessary to provide the service you explicitly requested — the calculator in the unit system you chose. No consent is required for this, which is why there is no cookie banner.

hc-recent is different, and we treat it differently. A list of pages you have visited is a convenience, not a necessity, so it is off until you switch it on. Nothing is written until you press the button on the home page that offers it; before that press, no such key exists and this site stores nothing about where you have been. That press is the consent required by section 25(1) TTDSG. The same block offers a button that stops the recording and deletes the list, and your browser settings can delete both values at any time.

What you type into a calculator

Everything you enter into a calculator is computed in your browser. The numbers never leave your device and never reach our server.

If you share a result via the address bar, your inputs are part of the URL — anyone you give that link to can see them. That is your decision, not ours.

Links to sources

Every calculator names the source of its figures. Those links lead to other people’s servers. Only when you click one does that provider learn your IP address; their own privacy policy governs what happens then. As long as you do not click, nothing is transmitted.

Your rights

You have the right of access (Art. 15 GDPR), rectification (Art. 16), erasure (Art. 17), restriction of processing (Art. 18), data portability (Art. 20), and objection to processing based on legitimate interests (Art. 21). Please use the email address above.

You also have the right to lodge a complaint with a supervisory authority (Art. 77 GDPR) — for our registered seat, the Saxon Commissioner for Data Protection and Transparency.