About SimpleFitCalc
SimpleFitCalc is a small collection of free health and fitness calculators built to be fast, private and transparent.
What we do
Each tool turns a well-known, published formula — such as the Mifflin-St Jeor equation for resting energy expenditure or the U.S. Navy circumference method for body fat — into a simple calculator. Every page explains how the formula works, walks through worked examples, lists its limitations, and links to the original research or the public-health body that publishes the guideline.
Our standards
- Cited formulas only. We use equations from peer-reviewed research or recognized organizations (CDC, NIH, WHO, the National Academies) and list those sources on every calculator.
- Estimates, clearly labeled. Formulas describe averages for groups of people. We say so plainly and point out who a result may not fit.
- Safety first. Our calorie tools never suggest intakes below common minimums (1,200 kcal/day for women, 1,500 for men) and recommend professional guidance for aggressive goals.
- Privacy by design. Calculations happen in your browser. We do not store or receive what you type.
Not medical advice
SimpleFitCalc is an informational resource, not a healthcare provider. Please read our Terms & Medical Disclaimer and talk to a qualified professional about your personal situation.
Corrections
Spotted an error or outdated source? A contact form is coming soon; we review and correct pages promptly.