What Velorsen does and does not do with your information. Last updated: 23 September 2026.
Velorsen is run by a single individual, who is the controller of any personal data this site processes. It is a personal project rather than a company, and the only contact detail published for it is the email address below.
Contact: velorsen@gmail.com, or through the contact page.
Each calculator reads the numbers you type, performs the arithmetic in your browser, and displays the result. Nothing is transmitted, so nothing is stored on a server. Closing the page discards it.
The site is hosted on Cloudflare Pages, so every request for a page or a file is handled by Cloudflare's network (Cloudflare, Inc.). There is no separate web server belonging to the operator, and no access logs of the operator's own.
To deliver the site, Cloudflare processes the technical data that any web request carries: your IP address, the page or file requested, the date and time, your browser's user-agent string, and similar request metadata. Cloudflare also uses that data to keep the site available and to detect and block abuse, such as automated scraping, bots and denial-of-service traffic. What Cloudflare does with that data, and how long it keeps it, is set out in Cloudflare's own privacy policy.
The legal basis is the legitimate interest in making the site available and keeping it secure (Article 6(1)(f) GDPR). Cloudflare may also set security cookies on some requests — see the cookies and local storage page.
The interface uses IBM Plex Sans and IBM Plex Mono, loaded from Google Fonts. To display the pages your browser requests the font files from Google's servers, which means your IP address and browser details reach Google. Google's handling of that information is described in its own privacy policy, and in How Google uses information from sites or apps that use our services.
The legal basis is the legitimate interest in displaying the site as designed. If you would rather not make that request, you can block remote fonts in your browser or with an extension: the pages remain fully usable and fall back to your system fonts.
Two entries — velorsen-theme and velorsen-workspace — are stored on your own device. They contain no identifier and are never sent anywhere. The cookies and local storage page explains them in full, including how to delete them.
The site uses Google Analytics 4 (measurement ID G-51HG3DGJ3D) to see which calculators and pages are actually used, where visitors arrive from, roughly which country they are in, and what devices and browsers they use. That is aggregate measurement, used to decide what to write and build next — not to identify anyone or to build a profile of a person.
When you agree to analytics through the consent message, Google sets cookies on this domain (_ga and _ga_51HG3DGJ3D) so that one visit can be told from another, and receives your IP address, the pages you view, and your browser and device details. Google states that Analytics 4 does not log or store IP addresses: the address is used to derive a coarse location and is then discarded.
Until you agree, the tag runs with consent denied — no analytics cookies are stored and no identifiers are used. Where consent is required, for visitors in the EEA, the UK and Switzerland, the legal basis is that consent (Article 6(1)(a) GDPR). Where it is not, the basis is the legitimate interest in understanding how the site is used (Article 6(1)(f) GDPR).
Google receives this data and processes it on the operator's behalf for measurement, so the operator decides what is measured; what Google does with it is described in Google's privacy policy and in How Google uses information from sites or apps that use our services. You can refuse or withdraw analytics consent in the consent message, and block or delete the cookies in your browser's settings — the cookies and local storage page explains how.
The site is free to use and is paid for by advertising, supplied by Google through its AdSense programme (publisher ID pub-7035206723276983). Google chooses which ads appear and measures how they perform; the operator sees only the aggregate reports Google provides, not who saw which ad, and advertising never affects a calculation or a result.
To serve and measure those ads, Google and the partners it works with may set cookies or read other identifiers in your browser, process your IP address and approximate location, note the page you are on, and — on this and other sites — record which ads you have seen. That includes profiling, which is why the site asks for your consent before a personalised ad is requested.
Where consent is required — for visitors in the EEA, the UK and Switzerland — personalised advertising is served only if you agree, through the consent message Google shows on the site. If you decline, ads are still shown, but they are not personalised using your browsing history. Google requires publishers to use a consent platform certified for that purpose, and its own message is the one used here.
The legal basis for personalised advertising, and for the storage it needs, is your consent (Article 6(1)(a) GDPR). For advertising that does not require consent, and for keeping the site and its advertising secure from fraud and abuse, the basis is legitimate interests (Article 6(1)(f) GDPR).
For the personal data involved in choosing and measuring ads, Google states that it acts as an independent data controller rather than as this site's processor. What it does with that data is set out in How Google uses information from sites or apps that use our services and on its advertising technologies page.
You can change your mind at any time: turn personalised advertising off for every site in Google's My Ad Center, use the industry opt-out portal Your Online Choices, clear the cookies already set in your browser's settings, or reopen the consent message — the cookies and local storage page has a button for that.
The operator does not sell, rent or share personal data for marketing, and keeps no visitor records to trade. Two companies receive anything: Cloudflare, which serves the site and protects it from abuse; and Google, which supplies the interface fonts, measures usage, and provides the advertising.
For the personal data involved in choosing and measuring ads, Google states that it acts as an independent controller rather than as this site's processor, so what Google does with that data is Google's own responsibility — it is described in Google's privacy policy rather than in this one.
Both operate infrastructure outside the EEA, so some of this processing involves an international transfer. Where that is the case, the transfer relies on the safeguards those providers put in place and describe in their own privacy documentation — for Google, its privacy policy and its data transfer framework pages.
Where the GDPR applies to you, you can ask for access to your personal data, its correction or erasure, a restriction on processing, or a copy in a portable form; you can object to processing based on legitimate interests; and you can withdraw any consent you have given, at any time, without that affecting what happened before. There is no automated decision-making or profiling on this site.
To exercise any of these, email velorsen@gmail.com. Because so little is held, in many cases the honest answer will be that nothing about you is stored here at all.
If you are not satisfied with how a request is handled, you can complain to the Irish Data Protection Commission (dataprotection.ie), or to the supervisory authority in your own country.
The consents this site asks for are for analytics and for personalised advertising, and they are asked for through Google's consent message. You can change or withdraw either at any time by reopening the message — the cookies and local storage page has a button that does exactly that — or by turning personalised advertising off in Google's My Ad Center. Withdrawing consent stops the cookie use it covered from that point on; it does not by itself remove cookies that have already been set, which your browser's settings can clear.
This site is written for a general engineering audience and is not directed at children. It has no accounts, no messaging and no feature that collects information from anyone, so no information is knowingly collected from children.
This policy describes the site as it is built today, and it is dated at the top. If the site changes in a way that affects privacy — for example if analytics is introduced, or a different advertising provider is used — this page will be updated before that change goes live, and the date above will change with it.
Questions about this policy, or about your data, go to velorsen@gmail.com, or through the contact page. The cookies and local storage page and the terms and conditions are the other pages worth reading.