Boer / James / Hume 公式估算瘦体重，用于精准代谢率和药物剂量。
feet
inches
55.1 kg
121.5 lbs
21.1%
14.7 kg of 69.9 kg
| Formula | LBM (kg) | LBM (lbs) | Implied body fat % |
|---|---|---|---|
| Boer (1984) | 56.0 | 123.5 | 19.8% |
| James (1976) | 56.5 | 124.6 | 19.1% |
| Hume (1966) | 52.8 | 116.5 | 24.3% |
Lean body mass (LBM) is everything in your body that isn't fat: muscle, bone, water, organs, and connective tissue. LBM matters for drug dosing (especially chemotherapy), basal metabolic rate (BMR), athletic performance, and nutritional planning. Our calculator averages the Boer, James, and Hume formulas — all three are validated regression equations that estimate LBM from height, weight, and sex. For precise body composition (and accurate fat %), DEXA scan remains the gold standard. This calculator is for educational use.
不同公式略有差异：
| 公式 | 男（1.8m / 80kg） | 女（1.65m / 60kg） |
|---|---|---|
| Boer | 64.4 kg | 41.0 kg |
| James | 62.6 kg | 41.9 kg |
| Hume | 61.3 kg | 42.0 kg |
LBM 与基础代谢 (BMR) 强相关。Katch-McArdle 公式 BMR = 370 + 21.6 × LBM(kg)，对运动员/肌肉量大者更准。体脂率 = (体重 − LBM) / 体重。
Cross-checked against authoritative formulas (IRS, NIST, ACSM) and updated for 2025/2026 tax years and rates.
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A lean body mass (LBM) calculator estimates the weight of everything in your body that isn't fat — muscle, bone, water, organs, and connective tissue. LBM is used for drug dosing (especially chemotherapy where dosing is based on BSA or LBM rather than total weight), basal metabolic rate (BMR) calculations, athletic performance planning, and body composition tracking. Our lean body mass calculator averages three validated regression formulas (Boer 1984, James 1976, Hume 1966) to give you a robust estimate from just height, weight, and sex.
How it works
Our lean body mass calculator averages the Boer (1984), James (1976), and Hume (1966) regression formulas to estimate LBM and inferred body fat %.
Toggle between US (lb, ft/in) and metric (kg, cm). The lean body mass calculator converts internally to kg and cm — the units used by all three formulas.
Type your height and weight. The lean body mass calculator uses sex to switch between male and female regression coefficients. All three formulas (Boer, James, Hume) use these inputs only.
The lean body mass calculator shows your LBM in kg and pounds (averaged across the three formulas), and an inferred body fat % from the gap between your weight and your LBM. Compare the three formulas in the table — they typically agree within 2-3 kg.
Estimate body fat percentage using the U.S. Navy tape method.
Calculate body mass index and see your weight category.
Find the healthy weight range for your height and frame.
Find your daily protein target by goal — RDA, endurance, strength, fat loss, or older adult.
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