An electrically-powered stationary device intended to use whole-body densitometry to determine body composition (percent and absolute body fat, and fat-free mass) based on manually-entered subject demographic data (e.g., age, gender, height), body weight, and body volume. The system includes controls and display, a scale for body weight measurement, and a closable cabin-like chamber with pre-calibrated air pressure sensors for determining body volume using air displacement plethysmography (by the application of pressure-volume relationships).