Health Calculators

Body Fat Calculator

Accurate body fat and lean body mass calculation via US Navy circumference method or Deurenberg clinical BMI formula.

Input Parameters

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Fast estimate without requiring tape circumference measurements. A clinical formula published in the British Journal of Nutrition (1991) by Prof. Deurenberg, predicting body fat percentage from BMI, age, and biological sex with high statistical validity.

US Navy Method (with tape measure)

Measure horizontally just below the larynx (Adam's apple)

⚠️ Measure horizontally across the navel at normal expiration (do not suck in stomach!) Measure horizontally at the natural narrowest point between ribs and hips

Measure horizontally at the maximal protrusion of buttocks with feet together

Calculation Result

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Evaluating...
Value Scale
Normal
Recommendations & Interpretation

Enter your parameters to view professional recommendations.

⚖️ Two-Component Body Composition

Tuk () Svaly a LBM ()
Fat Tissue Mass
Lean Body Mass (LBM)

🎯 Target Body Composition Simulator

I want to reach body fat %:
Target Body Weight
Pure Fat to Lose
čistého tuku

While preserving your current lean muscle mass (LBM) ().

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Využijte své výsledky v dalších kalkulačkách

Vaše beztuková hmota () umožňuje spočítat přesný metabolismus pomocí rovnice Katch-McArdle.

Scientific Methodology & Formula

The calculator uses the official logarithmic US Navy circumference method alongside the peer-reviewed clinical Deurenberg formula (1991) based on BMI and age.

ui.faq

How accurate is the US Navy method?

Studies demonstrate a correlation of over 0.90 with hydrostatic weighing and DEXA scans, making it the most reliable tape-measure estimation method available.

Why is waist measured at the navel for men instead of the narrowest point?

Men accumulate android adipose tissue predominantly around the umbilicus. Measuring at the narrowest point below ribs artificially underestimates waist circumference by 3–8 cm and skews fat percentage down by 3–5%.

What is the Deurenberg formula?

A clinical formula published in the British Journal of Nutrition (1991) by Prof. Deurenberg, predicting body fat percentage from BMI, age, and biological sex with high statistical validity.