Body Fat Calculator
Calculate body fat percentage accurately using the US Navy Logarithm formula. Also shows BMI, Lean Body Mass (LBM), and Basal Metabolic Rate (BMR). Free, no signup.
More Body Fat Calculations
How to use
- 1Select your gender (Male or Female) — the formula changes accordingly
- 2Enter your height, weight, and age
- 3Measure and enter neck, waist circumference (women add hip)
- 4View body fat %, BMI, LBM, BMR and personalized advice
Frequently Asked Questions — Body Fat Calculator
How accurate is the US Navy body fat formula?+
The US Navy formula has been validated against DEXA scans with an accuracy of ~1-3% margin. It is more practical than calipers (requires special skill) and more accessible than hydrostatic weighing. It is the standard method used by the US military for fitness assessments.
What is a healthy body fat percentage?+
Men: Essential (2–5%), Athletes (6–13%), Fitness (14–17%), Average (18–24%), Obese (>25%). Women: Essential (10–13%), Athletes (14–20%), Fitness (21–24%), Average (25–31%), Obese (>32%). The "Fitness" range is considered ideal for non-professional athletes.
What is Lean Body Mass (LBM)?+
Lean Body Mass is everything in your body except fat: muscles, bones, organs, and water. LBM = Weight × (1 − body fat ratio). Tracking LBM is more meaningful than scale weight alone — an increase in LBM indicates muscle gain even if total weight stays the same.