What this site is, what it isn't, and how you can use it.
Last updated: 12 October 2026
Fat Man's Journey (fatmansjourney.com) is operated by Karl Smith, a sole trader based in the United Kingdom. Contact: hello@fatmansjourney.com.
A collection of free online tools for estimating calorie needs, macro requirements, body mass index and body fat. All calculations run in your browser. There is no account, no login, and nothing is stored about you.
The tools and content on this site are for general information only and are not medical advice. They are not a substitute for consultation with a doctor, registered dietitian, or other qualified healthcare professional.
Always speak to a healthcare professional before making significant changes to your diet, exercise, or medication - especially if you have an existing medical condition, are pregnant, are under 18, or are taking prescription medication.
Every result on this site is an estimate based on population-average formulas such as Mifflin-St Jeor, Katch-McArdle, the Devine formula and the US Navy tape method. These formulas are well-established but they cannot account for your individual metabolism, medical history, genetics, or current health.
Results should be treated as a starting point for you to test and adjust based on your own real-world results - not as a precise prescription. See our FAQ for more on how accurate each tool is.
This site is provided "as is" and "as available". While care has been taken to get the formulas and calculations right, no warranty is given that the site will be error-free, uninterrupted, or that the results will be accurate for your particular circumstances. You use the site at your own risk.
To the fullest extent permitted by law, the operator of this site is not liable for any loss, injury, or damage arising from your use of the tools, reliance on any results, or any decisions you make based on the information provided.
Nothing in these terms limits liability for death or personal injury caused by negligence, fraud, or anything else that cannot lawfully be limited.
Some links on this site - particularly to Amazon products - are affiliate links. As an Amazon Associate, this site earns from qualifying purchases. This means if you click an affiliate link and buy something, the site may receive a small commission at no additional cost to you.
Affiliate links are only ever for products the operator actually uses or would recommend. They help cover the hosting and running costs of the site, which remains free to use. See the Privacy Policy for more on the cookies involved.
This site links to third-party sites such as Amazon, Cronometer and MyFitnessPal. Those sites have their own terms and privacy policies, and the operator of this site is not responsible for their content, practices, or availability.
The design, code, layout and written content of this site are the property of the site operator and are protected by copyright. You are welcome to:
You may not copy, reproduce, or republish substantial parts of the site without permission, use it for commercial purposes without agreement, or scrape it systematically.
Please use the site as intended. Do not:
The site may be updated, changed, or taken offline at any time without notice. These terms may also be revised from time to time - the date at the top shows when they were last updated. Continued use of the site means you accept the current version of these terms.
These terms are governed by the laws of England and Wales. Any disputes will be subject to the exclusive jurisdiction of the courts of England and Wales.
Any questions about these terms? Email hello@fatmansjourney.com.