The terms on which this site is provided. Last updated: 23 September 2026.
These terms govern your use of Velorsen ("the site"). By using the site you accept them; if you do not accept them, please do not use the site. They apply alongside the privacy policy, the cookies and local storage page and the engineering disclaimer.
The site is run by an individual, as a personal project, and can be contacted at velorsen@gmail.com.
Velorsen is a free collection of engineering calculators, formulas and explanations. It is provided for reference and learning. There is no account, no subscription and no charge, and no software is licensed or sold to you.
You may:
You must not:
The mathematics behind the calculators is standard engineering knowledge and is nobody's property. The written explanations, worked examples, page design, layout and code of this site are the work of the operator, and are protected by copyright. Your permission to use the site is the one set out in section 3, and nothing here transfers ownership of anything to you.
The calculators are believed correct for the assumptions each one states, and the outcomes are not guaranteed. They are not professional engineering advice and they are no substitute for engineering judgement. Please read the full engineering disclaimer before relying on a result, and verify anything that matters.
The site is hosted and protected by Cloudflare, its pages load interface fonts from Google Fonts, usage is measured with Google Analytics, and the advertising is supplied by Google, so using the site involves requests to those companies' servers; the privacy policy explains what that involves. Where the site links to another website, that site is not under the operator's control, and these terms do not apply to it.
Advertising on the site is supplied by Google through its AdSense programme, which is how the site is paid for. The ads are chosen by Google and not by the operator: they are not part of the calculators, no advertiser is endorsed, and the operator is not a party to anything agreed between you and an advertiser. Advertising never affects a calculation or a result. A complaint about a particular ad can be sent to velorsen@gmail.com and will be passed to Google, which is responsible for the ads it serves.
The site is provided as it is and as it is available. There is no guarantee of uninterrupted access, and calculators, pages or features may be changed, added or withdrawn at any time — for example while a mistake is being corrected. No charge is made for the site, and no service level or support commitment is offered.
The site may also be amended to add, change or withdraw features at any time. When a change affects privacy, the privacy policy and the cookies and local storage page are updated before it goes live.
The calculators and explanations are provided free of charge, and to the fullest extent the law allows the operator is not liable for any loss arising from reliance on them — including a decision made, a component chosen, a circuit built, or a mark lost, on the strength of a result from this site. That is why the disclaimer asks you to verify anything that matters.
Nothing in these terms excludes or limits liability where it cannot lawfully be excluded or limited, such as liability for fraud, for anything the law does not permit to be excluded, or for death or personal injury caused by negligence. Nothing here affects your statutory rights, including any mandatory consumer rights you have in your country of residence.
These terms are governed by the law of Ireland, and the Irish courts have jurisdiction, because the site is operated from Ireland. If you are a consumer resident elsewhere, this does not deprive you of the protection of the mandatory rules of the law of your own country, and you may also be able to bring proceedings there.
These terms are dated at the top and may be updated in future. The version published on this page is the one that applies, and continued use of the site after a change means you accept the updated terms.
Questions about these terms: velorsen@gmail.com, or the contact page.