How the Body Fat Calculator Works
This tool offers two methods for estimating body fat percentage. The US Navy method uses circumference measurements (neck, waist, and hips for women) along with height to calculate body fat using a logarithmic formula developed by the US Department of Defense. It is considered reasonably accurate for most people when measurements are taken correctly.
BMI-Based Estimate
The BMI-based method uses the Deurenberg formula: Body Fat % = (1.20 × BMI) + (0.23 × Age) − (10.8 × gender) − 5.4, where gender is 1 for males and 0 for females. While convenient (no tape measure needed), this method is less accurate for athletes, elderly individuals, or those with unusual body compositions.
Body Fat Categories
Body fat is categorised as essential (minimum for survival), athletes (competitive fitness), fitness (active lifestyle), acceptable (average), and obese (health risk). These ranges differ between men and women due to physiological differences.
Disclaimer: This tool provides estimates only and does not replace professional body composition analysis (e.g. DEXA scan, hydrostatic weighing). Consult a healthcare professional for accurate assessment and personalised advice.