FastCalcs

Terms of use

Last updated October 13, 2026

In short

  • FastCalcs is free to use, with no account needed.
  • Calculations are exact for your numbers, but they are a guide, not professional advice.
  • Don’t copy the site, scrape it, or use it to break the law.
  • You keep any consumer rights you have where you live.

These terms apply to your use of FastCalcs.app (“FastCalcs”, “we”, “us”), including every calculator, page and piece of content on the site. By using the site, you agree to these terms. If you don’t agree, please don’t use the site.

1. Who can use FastCalcs

FastCalcs is open to everyone, anywhere in the world. If you are under the age of majority where you live, please use the site with a parent or guardian’s permission. Our BMI, calorie and body fat calculators are designed for adults.

2. Results are a guide, not advice

Every result is calculated exactly from the numbers you enter, using the formulas and assumptions explained on each page. Real-world outcomes can still differ. Results are for general information and education only. They are not financial, legal, tax, medical, nutritional, engineering or other professional advice, and using the site does not create any professional relationship between you and us. Please read our full disclaimer.

You are responsible for checking that the numbers you enter are correct and that a result suits your situation before you act on it. For important decisions, such as a mortgage, a medical question or structural building work, talk to a qualified professional.

3. Acceptable use

You may use FastCalcs for your own personal or work purposes and share links to any page or result. You agree not to:

  • copy, republish or sell our pages, calculators, text or design, in whole or in large part, on another website or app;
  • place our pages inside a frame on another site or present them as your own;
  • scrape, crawl or download the site in bulk with automated tools, other than search engines indexing it under our robots.txt file;
  • try to break, overload, probe or bypass the security of the site or the services that host it;
  • use the site for anything unlawful, harmful or fraudulent.

4. Our content and name

The FastCalcs name, logo, design, text, formulas as written, code and other content belong to FastCalcs and are protected by copyright and other laws. Mathematical formulas themselves are not owned by anyone; our written explanations and our implementation of them are. Short quotes with a link back to the page are welcome.

5. Links to other websites

Some pages link to other websites, such as the official sources we cite. We don’t control those sites and aren’t responsible for their content, accuracy or privacy practices.

6. Advertising

FastCalcs may show advertising or links to partner products in the future to keep the calculators free. Ads will be labelled, will never change a calculator’s result, and will be described in our privacy policy before they appear.

7. No warranty

We work hard to keep every calculator accurate, tested and available. Even so, the site is provided “as is” and “as available”. To the fullest extent the law allows, we make no promises, express or implied, that the site will be error-free, uninterrupted, or fit for any particular purpose.

8. Limits of our liability

To the fullest extent the law allows, FastCalcs is not liable for any loss or damage that comes from using, or being unable to use, the site or its results. This includes financial loss, health decisions, material costs or project delays. Because the site is free, our total liability for any claim is limited to the amount you paid us to use it, which is zero.

Some countries do not allow certain warranties to be excluded or liability to be limited. In those places, these limits apply only as far as local law permits.

9. Your rights under local law

FastCalcs is used by people in many countries. Nothing in these terms takes away any rights you have as a consumer under the laws of the country where you live.

10. Changes to the site and these terms

We may add, change or remove calculators and content at any time. We may also update these terms; the date at the top shows when they last changed. If you keep using the site after a change, the updated terms apply.

11. Contact

Questions about these terms: hello@fastcalcs.app. See our contact page for more ways to reach us.