Calculate your fat-free body mass, body fat mass, and body fat percentage using the Boer formula
Lean Body Mass (LBM) is the total weight of your body minus all fat mass. It includes muscle, bone, organs, skin, and water. This calculator uses the Boer formula, one of the most accurate LBM estimation equations, to estimate your fat-free mass. Knowing your LBM helps you set accurate body composition goals.
Lean body mass and fat-free mass are often used interchangeably, but technically LBM includes a small percentage of essential fat (about 3% in men and 5% in women found in bone marrow, organs, and cell membranes). Fat-free mass (FFM) excludes all fat. The Boer formula estimates LBM.
To increase LBM, focus on resistance training (weight lifting), adequate protein intake (1.6-2.2 g per kg of body weight), and a slight calorie surplus. Consistency over months and years is key — muscle growth takes time. Sleep and recovery are equally important for muscle development.