Lean body mass calculator

Lean body mass (LBM) from height, weight and sex by the Boer, James and Hume formulas, with the implied body fat percentage.

업데이트 검증한 예제: 4

Accepts 5'11" or 5 ft 11 in
시도하기
Lean body mass (Boer)
kg
Lean body mass (Boer): 56.0 kg
소수 자릿수: 1; 가장 가까운 값, 중간값은 끝자리가 짝수인 쪽으로
James
56.5kg
Hume
52.8kg
Implied body fat (Boer)
20.0%

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.

Body composition (Boer)

20%fat
Lean mass56 kgFat mass14 kg
계산 방법 S
  1. Inputs in kilograms and centimetres

    w=70 kg,h=175 cmw = 70\ \text{kg},\quad h = 175\ \text{cm}
  2. Boer

    0.407×70+0.267×175−19.2=56.02 kg0.407 \times 70 + 0.267 \times 175 - 19.2 = 56.02\ \text{kg}
  3. James

    1.1×70−128×(70175)2=56.52 kg1.1 \times 70 - 128 \times \left(\frac{70}{175}\right)^2 = 56.52\ \text{kg}
  4. Hume

    0.32810×70+0.33929×175−29.5336=52.81 kg0.32810 \times 70 + 0.33929 \times 175 - 29.5336 = 52.81\ \text{kg}
  5. Implied body fat

    (1−56.0270)×100=20.0%\left(1 - \frac{56.02}{70}\right) \times 100 = 20.0\%

Lean body mass calculator 소개

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.

계산 예제

Man, 70 kg, 175 cm

Sex (for the formula)
Male
Weight
70 kg
높이
175 cm
Lean body mass (Boer)
56.0 kg
James
56.5 kg
Hume
52.8 kg
Implied body fat (Boer)
20.0%

검증 출처: 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

Woman, 60 kg, 165 cm

Sex (for the formula)
Female
Weight
60 kg
높이
165 cm
Lean body mass (Boer)
44.9 kg
James
44.6 kg
Hume
43.4 kg
Implied body fat (Boer)
25.2%

검증 출처: 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

Obesity: James falls below the others

Sex (for the formula)
Male
Weight
150 kg
높이
175 cm
Lean body mass (Boer)
88.6 kg
James
71.0 kg
Hume
79.1 kg

검증 출처: Python 3.8 decimal; James peaks at 1.1·175²/256 = 131.6 kg and declines beyond it (Green & Duffull 2002)

Imperial: 180 lb, 5 ft 10 in woman

Sex (for the formula)
Female
Weight
180 lb
높이
70 in
Lean body mass (Boer)
56.4 kg
James
56.2 kg
Hume
55.2 kg

검증 출처: Python 3.8 decimal after 180 lb = 81.6466 kg and 70 in = 177.8 cm

자주 묻는 질문

Is lean body mass the same as muscle mass?

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.

How is lean body mass calculated from height and 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.

Why does the James formula give low values for heavy people?

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.

What is a normal lean body mass percentage?

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.

“Lean body mass calculator”의 정확도는 어느 정도인가요?

정확도는 입력값과 계산 방법의 가정에 따라 달라집니다. 십진 연산은 유효숫자 50자리를 사용하지만, 추정값·수치해석 방법·원본 데이터의 정밀도는 더 낮을 수 있습니다. 표시값을 반올림해도 이러한 한계는 사라지지 않습니다. 독립적인 출처의 풀이와 대조한 계산 예시: 4. 예를 들어 “Man, 70 kg, 175 cm”은 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 − 29.5336와 대조해 확인합니다.

이 계산 방법의 출처는 무엇인가요?

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.

이 계산기 소개

Boer (M)=0.407w+0.267h−19.2(F)=0.252w+0.473h−48.3James (M)=1.1w−128(wh)2(F)=1.07w−148(wh)2Hume (M)=0.32810w+0.33929h−29.5336(F)=0.29569w+0.41813h−43.2933\begin{aligned}\text{Boer (M)} &= 0.407w + 0.267h - 19.2 & \text{(F)} &= 0.252w + 0.473h - 48.3\\ \text{James (M)} &= 1.1w - 128\left(\tfrac{w}{h}\right)^2 & \text{(F)} &= 1.07w - 148\left(\tfrac{w}{h}\right)^2\\ \text{Hume (M)} &= 0.32810w + 0.33929h - 29.5336 & \text{(F)} &= 0.29569w + 0.41813h - 43.2933\end{aligned}

출처

  1. Boer P. Estimated lean body mass as an index for normalization of body fluid volumes in humans. Am J Physiol 1984;247:F632–F636
  2. James WPT. Research on obesity. London: HMSO, 1976 (DHSS/MRC Group report)
  3. Hume R. Prediction of lean body mass from height and weight. J Clin Pathol 1966;19:389–391
  4. 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

정보 제공용이며 의료 조언이 아닙니다. 이 공식은 집단을 설명하며 개인의 상태를 평가하지 않습니다. 결과에 따라 행동하기 전에 의료진과 상담하세요.

출처와 대조하여 검증

이 계산기에는 독립적인 출처에서 답을 얻은 계산 예제가 4개 있습니다. 테스트 모음에서 실행되며 여기에서도 실행할 수 있습니다.

관련 계산기