Lean body mass (LBM) from height, weight and sex by the Boer, James and Hume formulas, with the implied body fat percentage.
更新日 検証済みの例：4
About 56 kg of your 70 kg is lean mass by the Boer formula, leaving roughly 20 % as fat; the 3 formulas range from 52.8 to 56.5 kg.
Lean body mass (LBM) is body weight minus fat: muscle, bone, organs, skin and body water. It is estimated here from height, weight and sex with three regression formulas, Boer (1984), James (1976) and Hume (1966). Subtracting the Boer estimate from your weight gives an implied body fat percentage.
Clinicians use LBM to scale some drug doses and fluid volumes, and the Katch-McArdle equation uses it to estimate resting energy needs. For a man weighing 70 kg at 175 cm the three formulas give 52.8 to 56.5 kg, and Boer's 56.0 kg implies about 20 % body fat.
The formulas assume average body composition for a given height and weight, so they cannot see unusual muscle or fat. The James formula peaks and then falls as weight rises, which underestimates lean mass in obesity (Green and Duffull, 2002). A tape or skinfold measurement adds information about your own build.
照合元：Python 3.8 decimal: 0.407·70 + 0.267·175 − 19.2; 1.1·70 − 128·(70/175)²; 0.32810·70 + 0.33929·175 − 29.5336
照合元：Python 3.8 decimal: 0.252·60 + 0.473·165 − 48.3; 1.07·60 − 148·(60/165)²; 0.29569·60 + 0.41813·165 − 43.2933
照合元：Python 3.8 decimal; James peaks at 1.1·175²/256 = 131.6 kg and declines beyond it (Green & Duffull 2002)
照合元：Python 3.8 decimal after 180 lb = 81.6466 kg and 70 in = 177.8 cm
No. Lean body mass is everything that is not fat: muscle, bone, organs, skin, blood and body water. Skeletal muscle is the largest part but not all of it. In an MRI study of 468 adults, Janssen and colleagues (2000) measured skeletal muscle at 38.4 % of body weight in men and 30.6 % in women, while a man with 20 % body fat has lean mass equal to 80 % of his weight.
With a regression formula fitted to measured body composition. Boer's is 0.407 × weight + 0.267 × height − 19.2 for men and 0.252 × weight + 0.473 × height − 48.3 for women, with weight in kg and height in cm. For a 60 kg woman 165 cm tall that gives 44.9 kg, which implies 25.2 % body fat, in the ACE average range for women.
Its squared term, 128 × (weight ÷ height)² for men, grows faster than the 1.1 × weight term, so estimated lean mass peaks and then falls as weight rises. At 175 cm the peak for men is at 131.6 kg, and a 150 kg man gets 71.0 kg against Boer's 88.6 kg. Green and Duffull (2002) cautioned against using it as a size descriptor for obese patients.
It is 100 % minus body fat percentage. The American Council on Exercise's average body fat ranges, 18–24 % for men and 25–31 % for women, correspond to lean mass of 76–82 % and 69–75 % of body weight. Athletes sit higher: ACE's athlete ranges of 6–13 % and 14–20 % fat mean 87–94 % and 80–86 % lean mass.
精度は入力値と計算方法の前提に依存します。十進演算には有効数字50桁を使いますが、推定、数値計算手法、元データの精度はそれより低い場合があります。表示の丸め処理でこれらの制約がなくなるわけではありません。 独立した出典の解答と照合した計算例：4。 例えば、「Man, 70 kg, 175 cm」はPython 3.8 decimal: 0.407·70 + 0.267·175 − 19.2; 1.1·70 − 128·(70/175)²; 0.32810·70 + 0.33929·175 − 29.5336と照合しています。
Boer P. Estimated lean body mass as an index for normalization of body fluid volumes in humans. Am J Physiol 1984;247:F632–F636; James WPT. Research on obesity. London: HMSO, 1976 (DHSS/MRC Group report); Hume R. Prediction of lean body mass from height and weight. J Clin Pathol 1966;19:389–391; Green B, Duffull SB. Caution when lean body weight is used as a size descriptor for obese subjects. Clin Pharmacol Ther 2002;72:743–744.
情報提供のみで、医療上の助言ではありません。これらの式は集団を表すもので、個人の状態を評価するものではありません。結果に基づいて行動する前に医療専門家へ相談してください。
この計算機には、独立した出典の解答を使った計算例が 4 件あります。テストに組み込まれており、ここでも実行できます。
米海軍の周囲長法、Jackson-Pollockの3点・7点皮下脂肪厚法、またはBMIから体脂肪率を推定し、脂肪量・除脂肪量とACE区分を表示します。
Mifflin-St Jeor、Harris-Benedict、Katch-McArdleの式で基礎代謝量（BMR）を推定し、5段階の活動量に応じた1日の必要カロリー（TDEE）を計算します。
メートル法またはヤード・ポンド法の身長と体重からBMIを計算し、WHOの成人向け区分と身長に応じた健康的な体重範囲を表示します。
身長と性別からDevine、Robinson、Miller、Hamwiの式で理想体重を計算し、健康的なBMIに対応する体重範囲を表示します。
Body surface area (BSA) in m² from height and weight by the Mosteller, DuBois and Haycock formulas, with the spread between them.
Waist-to-hip ratio and waist-to-height ratio from tape measurements, with the WHO risk cut-offs, the NICE bands and the WHO waist size category.