Body Fat Percentage Calculator
Accurately estimate your body fat percentage and body composition without specialized clinical equipment using the validated US Navy circumference tape formula. Simply measure your neck, waist (and hips for females) alongside height and body weight.
Formula utilizes sex-specific adipose distribution equations
Current body weight in kilograms
Standing barefoot height in centimetres
Measured just below the laryngeal prominence (Adam’s apple)
Men: horizontally at navel level. Women: horizontally at narrowest point of torso.
Measured horizontally at the point of greatest gluteal circumference
Calculated using the US Navy body fat circumference equation
How to Use This Calculator
- Measure your neck circumference just below the Adam’s apple with a non-elastic tape.
- For men, measure waist circumference horizontally at the naval. For women, measure at the narrowest waist point and widest hip point.
- Ensure the measuring tape remains level around your body without compressing the skin.
- Enter your measurements above to reveal your body fat percentage and lean tissue mass.
Formula & Calculation Methodology
The US Navy formula estimates body density using logarithmic circumference transformations of the neck, waist, and hips. Percent body fat is then derived using the Siri equation.
Worked Example
A male weighing 78 kg, height 178 cm, neck 38 cm, waist 84 cm
Frequently Asked Questions
How accurate is the US Navy body fat formula compared to DEXA?↓
Validation studies by the US Department of Defense indicate that the US Navy tape method correlates within 3% to 4% of dual-energy X-ray absorptiometry (DEXA) and hydrostatic weighing when measurements are carefully gathered.
What is essential body fat and why is it vital?↓
Essential fat represents the minimal adipose tissue required for physiological function, thermal insulation, organ protection, and hormonal synthesis (3–5% for men, 10–13% for women). Dropping below this baseline causes severe endocrine disruption.
Why does the female formula include a hip circumference measurement?↓
Due to biological hormonal differences, women naturally store subcutaneous adipose tissue primarily around the hips, thighs, and pelvis (gynoid distribution), whereas men accumulate visceral and subcutaneous fat primarily around the abdomen (android distribution).
When is the best time of day to take circumference measurements?↓
Take measurements in the morning before eating breakfast, after voiding your bladder, and at the end of a normal, relaxed exhalation to eliminate digestive bloating variance.
What is the main limitation of the US Navy tape method?↓
Circumference formulas can overestimate fat percentage in individuals with atypical muscle-to-bone proportions or individuals carrying significant abdominal water retention. A DEXA scan remains the gold standard for clinical confirmation.
Related Calculators
BMI Calculator
Open calculator →Lean Body Mass Calculator
Open calculator →Ideal Weight Calculator
Open calculator →Waist to Hip Ratio Calculator
Open calculator →Calorie Calculator
Open calculator →BMR & TDEE Calculator
Open calculator →Macro Calculator
Open calculator →Body Surface Area Calculator
Open calculator →Source Citation & Disclaimer
Informational tool only; not licensed tax, legal, or financial advice.