Lean Body Mass Calculator for Women
Estimate your lean body mass with the female formula coefficients pre-selected. Enter your height and weight, or a measured body fat % for an exact figure.
Lean Body Mass Calculator for Women
Required: the lean-mass formulas use biological sex (male or female) as a variable.
Range: 30–300 kg
Enter your height in centimeters (e.g., 170 cm)
Used only to flag whether the result needs an under-19 caveat — it does not change the formula. Leave blank if you'd rather not say.
Know your body fat %? Enter it for the most accurate result (lean mass = weight × (1 − body fat%)). Leave it blank to use the height & weight formulas. Don't know it? Estimate it with the Body Fat % Calculator.
The average of the Boer, James and Hume estimates — the most balanced default. A measured body fat % above always overrides the formula estimate.
*This calculator is for informational purposes only. Please consult a healthcare professional before making any health decisions. See our medical disclaimer for more information.
Quick Answer
Lean Body Mass for Women
This page loads the lean body mass calculator with female pre-selected, so the formulas use the coefficients derived for women. Lean body mass is everything that is not fat — muscle, bone, organs and water — and for women it is commonly a somewhat lower share of body weight than for men, reflecting higher essential fat. Enter your height and weight above for an estimate, or add a measured body fat % for an exact figure.
Why Sex Is a Variable in the Formula
The lean-mass formulas ask for biological sex for one plain reason: on average, women and men of the same height and weight differ in how that weight is divided between fat and lean tissue. Women typically carry a higher proportion of essential fat — the fat built into reproductive and hormonal function — and a somewhat smaller share of lean tissue. The Boer, James and Hume equations encode that average by using a different constant or multiplier for female bodies, so the same height and weight produce a different lean-mass estimate depending on the sex entered. It is important to be clear about what this is and is not: it is a statistical adjustment for a population average, not a statement that one body is better than another. Real women vary enormously around that average, which is exactly why a measured body fat percentage always trumps the sex-based estimate.
A Worked Example for a Woman
Take a woman who is 165 cm and 65 kg. Run her numbers through the three formulas and they land close together but not identical: the Boer estimate is about 46.1 kg of lean mass, James about 46.6 kg, and Hume about 44.9 kg. Their average is roughly 45.9 kg, which would mean a lean-mass share of about 71% of her body weight and, by definition, a body fat of around 29%. Those are the figures the tool above produces for those inputs. The spread of about one and a half kilograms between the formulas is normal and comes from their different origins — it is the reason showing all three, plus the average, is more honest than presenting a single number as fact.
Making the Number More Accurate
The single best upgrade to a formula estimate is a measured body fat percentage. Get one from the Body Fat % Calculator and enter it above, and the tool will report your lean mass exactly as weight minus fat mass instead of estimating it. Once you know your lean tissue, protecting it is what makes a fat-loss phase go well, and a sensible daily protein target from the Protein Intake Calculator is the main lever for that alongside resistance training. For the general version of this tool with the formula selector exposed, use the Lean Body Mass Calculator.
Lean mass is estimated with the Boer (1984), James (1976) and Hume (1966) formulas using the female coefficients, or computed directly from a measured body fat %. Typical ranges are descriptive of what is commonly observed, not targets. These figures are general estimates for education, not medical advice.
Precision Tracking Tools
Monitor your baseline metrics with clinical accuracy to ensure you stay on target.
Custom Meal Design
Access foundational dietary blueprints structured for sustainable, long-term success.
Expert Coaching
Connect with certified professionals who can tailor strategies to your unique physiology.
Explore More Tools
Each calculator feeds into the next — your data carries forward automatically through every step.
Lean Body Mass
Find your lean mass and fat mass from height, weight and sex (Boer, James, Hume) — or directly from a measured body fat %.
Body Fat %
Determine your body composition and lean mass using the clinically validated US Navy circumference method.
Protein Intake
How much protein to eat per day for fat loss, maintenance or muscle gain — a science-based range from your body weight or lean mass, not a single guess.