Terms of use

The tools are free, there is nothing to sign up to, and you may use them for anything you like. What follows is mostly about the limits of what they can tell you, because that is the part that could actually cost somebody something.

The tools are free and unconditional

No account, no payment, no registration. You may use any tool on this site for personal or commercial purposes. Results you generate are yours — a username, a block of fancy text or a calculation is not claimed as anyone's property.

What the results are, and what they are not

Every tool here states its own confidence, and that statement is the important part of the answer. Where a result says a date is exact, it is exact within what the source supports. Where it says two years are possible, both genuinely are, and no amount of re-reading will narrow it.

Specifically:

• The guitar and VIN pages are reference tools, not authentication. They will not tell you whether an instrument is genuine, and a decoded date is not a provenance document. For anything valuable, get a written appraisal from somebody qualified.
• The health tools are not medical advice. The calorie and BMI pages follow published equations and NHS or NICE thresholds and say where those come from. They do not know anything about you beyond the numbers you typed.
• The SIP calculator is not financial advice. It projects arithmetic forward at a rate you choose. Investments can fall.
• The random number generator is not suitable for regulated gambling or for anything requiring certified randomness, and says so on its own page.

Sources, and why they are named

Where a tool relies on somebody else's published work, that work is named and linked on the page. Sources are cited so that you can check them, and because the people who compiled them deserve the credit. Some sources are the manufacturers themselves; some are researchers and collectors; and where a source could not be used, the page says so and points you at it instead.

If you are one of those sources and you would rather your work were not reproduced here, say so and it will be removed. That is not a grudging offer. It has already happened more than once.

Accuracy, and the honest limit of it

These tools are built carefully and checked automatically, and they will still sometimes be wrong — because a source was wrong, because a manufacturer contradicted themselves, or because of a mistake made here. They are provided as they are, with no warranty of any kind.

Decisions with money or health attached should not rest on a free web page, this one included. To the fullest extent the law allows, no liability is accepted for any loss arising from the use of this site. Nothing here limits liability for death or personal injury caused by negligence, or for fraud, because the law does not allow that to be limited and it should not be.

Availability

The site may be changed, moved or taken down at any time without notice. Tools may be added or removed. There is no undertaking that any page will keep working or keep existing.

The content of this site

The words, code and layout of this site are its author's. The underlying facts — serial number ranges, published equations, the contents of manufacturers' charts — are facts, and facts belong to nobody.

Law

This site is operated from the United Kingdom, and these terms are governed by the law of England and Wales.

Changes

This page lives in the same source repository as the site, so every change to it is recorded with a date and a reason. It was last changed on 11 September 2026.