Verified Mathematical Model & Formulation
Men %Fat = 86.010 × log10(waist - neck) - 70.041 × log10(height) + 36.76 Women %Fat = 163.205 × log10(waist + hip - neck) - 97.684 × log10(height) - 78.387 Fat Mass = Weight × (%Fat / 100) Lean Mass = Weight - Fat Mass
Uses logarithmic circumference equations developed by the US Naval Health Research Center to estimate body density and subcutaneous/visceral fat tissue without hydrostatic weighing or DEXA.
Configurable Parameters & Standard Units
- Biological Sex (1=Male, 2=Female): (Default: 1 count)
- Body Weight (kg): (Default: 78 kg)
- Height (cm): (Default: 178 cm)
- Neck Circumference (cm): (Default: 38 cm)
- Waist Circumference (cm): (Default: 86 cm)
- Hip Circumference (cm) [Females only]: (Default: 96 cm)
Standard Worked Example & Practical Verification
Scenario: A male weighing 80 kg, 178 cm tall, with neck 39 cm and waist 84 cm.
Practical Takeaway: Puts the user in the healthy fitness category for adult males.
Frequently Asked Questions
What is considered an ideal body fat percentage?
For men: Essential fat is 2-5%, Athletes 6-13%, Fitness 14-17%, Average 18-24%, Obese 25%+. For women: Essential fat is 10-13%, Athletes 14-20%, Fitness 21-24%, Average 25-31%, Obese 32%+.
How accurate is the US Navy method compared to DEXA?
Studies show the US Navy tape method correlates within 3% to 4% of dual-energy X-ray absorptiometry (DEXA) scans for the vast majority of healthy adults.