Lean Body Mass Calculator
Calculate your lean body mass (total weight minus fat) from your weight and body fat percentage.
Lean Body Mass
— kg
Fat Mass
— kg
Lean body mass includes muscle, bone, organs, and water. Track it over time to ensure you are losing fat, not muscle.
About this calculator
Lean body mass (LBM) is everything in your body that is not fat: muscle, bone, organs, water, and connective tissue. Tracking LBM alongside your total weight gives you a much clearer picture of what is happening during a fat loss or muscle-building phase. If your weight drops but your LBM stays the same, you are losing primarily fat, which is exactly what you want. If LBM is dropping too, you may need more protein or a smaller deficit. LBM also determines your baseline calorie needs more accurately than total weight, since muscle is metabolically active tissue that burns calories at rest. Many coaches use LBM rather than total body weight when setting protein and calorie targets for clients.
Frequently asked questions
Why is lean body mass more useful than total weight?
Total weight lumps muscle and fat together, making it impossible to tell what you are actually gaining or losing. Someone who loses 5 lbs of fat and gains 3 lbs of muscle has only lost 2 lbs on the scale, but their body composition improved dramatically. Tracking LBM separates signal from noise.
How do I increase my lean body mass?
Resistance train consistently (3-5 days per week), eat adequate protein (1.6-2.2 g/kg of body weight), and ensure you are not in too aggressive a calorie deficit. Progressive overload, gradually increasing weight, reps, or volume over time, is the primary driver of muscle growth.
What is a good lean body mass for my height?
This varies widely based on genetics, training history, and gender. As a rough benchmark, a lean and muscular male at 5'10" might carry 150-170 lbs of lean mass. A female at 5'5" might carry 100-120 lbs. Focus on your personal trend over time rather than absolute numbers.
These numbers are a starting point. If you want help turning them into a plan you'll actually stick to, I do 1-on-1 coaching.
Learn more about coaching →Related Calculators
Related Articles
- How to Track Your Progress
Move beyond the scale. Learn to track what truly matters for a holistic and motivating view of your fitness progress: from strength and measurements to energy and sleep.
- Exercise Part One: Why Movement Matters
Understanding the SRA cycle and how movement rebuilds the body stronger than before - the foundation of effective training for transformation.