About FitNumbra

Why FitNumbra exists

Numbers like BMI, calories and protein targets come up constantly in conversations about health — but the tools that calculate them are often cluttered, confusing or buried behind sign-ups. FitNumbra was created to offer a calm, straightforward alternative: quick calculators that work well on any device, with plain-English explanations of what each number means and where it comes from.

What we offer

• 12 free calculators covering body measurements, daily energy needs, nutrition targets and handy unit conversions — see all calculators.
• Clear guides that explain the ideas behind the numbers — browse the FitNumbra blog.
• No accounts, no paywalls. Every tool is free to use.

How our calculators are built

Every FitNumbra calculator uses established, published methods rather than invented formulas. For example:

• BMI categories follow the World Health Organization adult classification.
• Calorie, BMR and TDEE estimates use the Mifflin–St Jeor equation with standard activity multipliers.
• Protein ranges reflect the RDA and the International Society of Sports Nutrition position stand.
• Body-fat estimates use the U.S. Navy circumference method.

Each calculator page shows the formula it uses, a worked example, its limitations and the sources behind it. Inputs are validated so results are always within realistic ranges, and every calculation is covered by automated tests.

Editorial standards

• We describe results as estimates and general guidance — never as a diagnosis.
• We cite the research and public-health guidance our tools and articles are based on.
• We avoid sensational claims, quick fixes and product promotion in our content.
• We review content periodically and correct errors as soon as we learn about them.

FitNumbra is an information service, not a healthcare provider. Please read our medical disclaimer and speak to a qualified professional about your personal health.

Your privacy

Calculations run in your browser. We do not ask for your name, and the measurements you enter are not sent to or stored on our servers. Read the full privacy policy.

Get in touch

Spotted a mistake, have a suggestion or want to ask a question? Email us at contact@muhammadbaqir.com or visit the contact page.