These calculators are tools for estimating, not for deciding. Every one of them shows its formula and a worked example so you can check the arithmetic yourself — but arithmetic is not the same as advice, and this page sets out where that line falls.
The short version
| What these are | Estimates from published formulas, calculated in your browser |
| What they are not | Financial, tax, legal, medical, engineering or construction advice |
| Who checks the result | You, before acting on it |
| Who is responsible for a decision | The person who makes it |
| What we accept liability for | Nothing arising from use of these tools, to the extent the law allows |
| What the law does not allow us to disclaim | Stays with us — see the last section |
No liability for outcomes
The tools on this site are provided as they are, without warranty of any kind. To the fullest extent permitted by law, no liability is accepted for any loss, cost, damage or missed opportunity arising from the use of, or reliance on, anything on this site — whether the figure was right, wrong, misread or misapplied.
That includes, without limiting it: a loan that costs more than the estimate suggested, a tax position that turned out differently, a structure built to a figure from a page, a diet or exercise plan that did not suit you, a business decision taken on a projection, and time or money spent as a result of any of these.
Where estimates go wrong
A calculator can be arithmetically perfect and still mislead. The common reasons are worth knowing, because they are the ones you can do something about:
| Cause | What happens |
|---|---|
| The inputs | A guessed figure produces a confident-looking answer built on a guess. Most large errors start here |
| Rounding conventions | Lenders, tax authorities and engineers round in ways that differ from each other and from a general-purpose page |
| Local rules | Rates, thresholds, codes and standards vary by country and change year to year |
| Model limits | Population formulas describe an average. You may sit well outside it and nothing in the equation will say so |
| The wrong tool | A formula that fits one case gives a plausible and wrong answer for another |
| Stale figures | Anything involving current rates or prices is only as fresh as the last update |
Where professional advice is not optional
Some decisions should not be made from a web page at all. In these areas the tools are a starting point for a conversation, not a substitute for one:
| Area | Talk to | Because |
|---|---|---|
| Loans and mortgages | The lender, or a regulated adviser | Real offers depend on credit, fees and terms no page can see |
| Tax | An accountant or your tax authority | Rates, reliefs and thresholds are jurisdiction-specific and change annually |
| Investment and retirement | A regulated financial adviser | Projections assume steady returns. Real ones arrive unevenly, and the order matters |
| Health, diet and fitness | A doctor or registered dietitian | Equations describe populations. Conditions, medications and pregnancy change everything |
| Structural and electrical work | A qualified engineer | Local codes, safety factors and material grades decide whether something is safe |
| Legal questions | A lawyer in your jurisdiction | Nothing on this site is legal advice, including this page |
Accuracy, and what we do about it
Formulas are taken from published sources and checked against a hand-computed example before a tool goes live. Sources are named on the pages where the figures are contested or where a reader might reasonably want to look them up.
Despite that, errors happen. If you find one, please tell us — corrections are made as quickly as they can be verified, and a wrong calculator helps nobody. No claim is made that any tool is free of error, that it is current, or that it is fit for any particular purpose.
Your files stay yours
Several tools here work on documents you provide — PDFs, images, Markdown. Those files are read by your own browser and never uploaded, which you can confirm in the network panel of your browser's developer tools. Nothing is stored, transmitted or retained.
Output from those tools carries no watermark, no added page and no branding of ours: your document is yours. Calculator results do carry an attribution line, because the calculation is ours — the input is still yours, and nothing you type is recorded.
Third-party links and content
Some pages link to external sites and some carry advertising. Linking is not endorsement, and we have no control over what a third party publishes, charges or does with information you give them. Any dealing with an external site is between you and them.
Where a link is a paid or affiliate arrangement, it is marked as such on the page it appears on.
Availability
Nothing here is guaranteed to be available, uninterrupted or free of defects. Tools may change or be withdrawn without notice, and some depend on a library fetched from a content delivery network that we do not operate. A calculation you need to keep should be printed or copied at the time, not left here to be found again.
What cannot be excluded
Nothing on this page limits liability where the law does not allow it. In particular, and regardless of anything above:
- Liability for death or personal injury caused by negligence
- Liability for fraud or fraudulent misrepresentation
- Any right you have as a consumer that cannot be excluded under the law of your country
Consumer protection law in many countries limits what a website can disclaim, and where a term on this page conflicts with a right you hold, your right applies and that term does not. If any part of this page is found unenforceable, the rest stands.
Questions
If anything here is unclear, or you think a tool is wrong, the contact page is the place to say so. See also the terms of use and the privacy policy, and about us for how the site is built.
This page is written in plain language on purpose. It is not legal advice and was not drafted by a lawyer; if you need terms that will be tested, have them reviewed by one.