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PesaFit
PesaFit

Body composition calculator (Navy method)

Nutrition

By Jesús Narváez Tamés ·

Estimate your body-fat % with the Navy method (tape measure). You only need to measure neck and waist (and hips for women).

Just below the Adam's apple

At the navel

Your body-fat %
23.5%
Classification
Average
Fat mass
17.6kg
Lean mass
57.4kg

ACE scale (men)

BF %: 23.5

6141825
  • Essential fat
  • Athletes
  • Fitness
  • Average
  • Obese

Body composition

Lean mass57.4 kg
Fat mass17.6 kg
Disclaimer: this calculator provides educational information and estimates based on standard formulas. It is not a substitute for personalised advice from a doctor, nutritionist or trainer. Consult a professional before making significant changes to your diet or training.

Knowing your body composition (% fat, % lean mass) is much more informative than weight or BMI, but it usually requires expensive machines like DEXA. The Navy method is the best at-home alternative.

How the Navy method works

Developed by the US Navy to estimate body composition without equipment. It uses height and circumferences (neck, waist and, for women, hip) in logarithmic formulas. Margin of error ±3% versus DEXA, enough to follow month-to-month trends.

How to measure well

Use a flexible (not metallic) tape, without squeezing. Morning, fasted, relaxed posture. Neck: just below the Adam's apple. Men's waist: at navel level. Women's waist: at the narrowest point. Hip: at the widest. Repeat twice and average.

Frequently asked questions

How accurate is the Navy method?+

Margin of error ±3% versus DEXA. It's the best option without specialised equipment as long as you measure carefully (loose tape, correct position).

Where do I measure the waist?+

Men: at navel level. Women: at the narrowest point between ribs and hips.