BSA, BMI, LBW, IBW calculator v. 2.2

Calculate body surface area, body mass index, lean body weight, ideal body weight

Note: for calculation of Body shape index (BSI) please enter your "waist line".

Body surface area (BSA)

Formula Result
Mosteller's formula
DuBois and DuBois's formula
Haycock's at al. formula
Gehan and George's formula
Boyd's formula
Fujimoto's formula
Takahira's formula
Shuter and Aslani's formula
Schlich's formula for men
Schlich's formula for women
Costeff's formula (based on body weight)
Mattar's formula
Livingston and Scott's formula
Yu's et al. formula
EPA's formula
Average value by all formulas

Body mass index (BMI) and Body shape index (BSI)

Formula Result
Body mass index
Body shape index

Lean body weight (LBW)

Formula Result
James's method for men
James's method for women
Hume's method for men at the age of 16-60 years
Hume's method for women older than 30 years

Ideal body weight

Formula Result
Devine's formula for men
Devine's formula for women
Hamwi's method for men
Hamwi's method for women

Formulas for calculated parameters

Body surface area (in one calculator collected nearly all available formulas):

  • Mosteller's formula (Reference)

    BSA (m2) = ((Height (cm) × Weight (kg)) ÷ 3600)0.5

  • DuBois and DuBois's formula (Reference)

    BSA (m2) = 0.007184 × Height (cm)0.725 × Weight (kg)0.425

  • Haycock's at al. formula (Reference)

    BSA (m2) = 0.024265 × Height (cm)0.3964 × Weight (kg)0.5378

  • Gehan and George's formula (Reference)

    BSA (m2) = 0.0235 × Height (cm)0.42246 × Weight (kg)0.51456

  • Boyd's formula (Reference)

    BSA (m2) = 0.0003207 × Weight (g)(0.7285 - 0.0188 × log10 Weight (g) × Height (cm)0.3

  • Fujimoto's formula (Reference)

    BSA (m2) = 0.008883 × Height (cm)0.663 × Weight (kg)0.444

  • Takahira's formula (Reference)

    BSA (m2) = 0.007241 × Height (cm)0.725 × Weight (kg)0.425

  • Shuter and Aslani's formula (Reference)

    BSA (m2) = 0.00949 × Height (cm)0.655 × Weight (kg)0.441

  • Schlich's formula for men (Reference)

    BSA (m2) = 0.000579479 × Height (cm)1.24 × Weight (kg)0.38

  • Schlich's formula for women (Reference)

    BSA (m2) = 0.000975482 × Height (cm)1.08 × Weight (kg)0.46

  • Costeff's formula (based on body weight) (Reference)

    BSA (m2) = (4 × Weight (kg) + 7) ÷ (90 + Weight (kg))

  • Mattar's formula (Reference)

    BSA (m2) = (Height (cm) + Weight (kg) - 60) ÷ 100

  • Livingston and Scott's formula (Reference)

    BSA (m2) = 0.1173 × Weight (kg)0.6466

  • Yu's et al. formula (Reference)

    BSA (m2) = 0.015925 × (Height (cm) × Weight (kg))0.50

  • EPA's formula (Reference)

    BSA (m2) = 0.0239 × Height (cm)0.417 × Weight (kg)0.517

Body mass index (BMI) and Body shape index (BSI):

  • Body mass index (Reference)

    BMI (kg/m2) = Weight (kg) ÷ Height (m)2

  • Body shape index (Reference)

    BSI (kg/m2) = Waist line (m) ÷ (BMI (kg/m2)2/3 × Height (m)1/2)

Lean body weight (LBW):

  • James's method for men (Reference)

    LBW (kg) = 1.10 × Weight (kg) - 128 × (Weight (kg)2 ÷ Height (cm)2)

  • James's method for women (Reference)

    LBW (kg) = 1.07 × Weight (kg) - 148 × (Weight (kg)2 ÷ Height (cm)2)

  • Hume's method for men at the age of 16-60 years (Reference)

    LBW (kg) = 0.32810 × Weight (kg) + 0.33929 × Height (cm) - 29.5336)

  • Hume's method for women older than 30 years (Reference)

    LBW (kg) = 0.29569 × Weight (kg) + 0.41813 × Height (cm) - 43.2933)

Ideal body weight (IBW):

  • Devine's formula for men (Reference)

    IBW (kg) = 50 (kg) + 2.3 (kg) × (Height (cm) × 2.54 - 60)

  • Devine's formula for women (Reference)

    IBW (kg) = 45.5 (kg) + 2.3 (kg) × (Height (cm) × 2.54 - 60)

  • Hamwi's formula for men (Reference)

    IBW (kg) = 48 (kg) + 2.7 (kg) × (Height (cm) × 2.54 - 60)

  • Hamwi's formula for women (Reference)

    IBW (kg) = 45 (kg) + 2.3 (kg) × (Height (cm) × 2.54 - 60)

Reference values for some parameters

Body surface area (BSA) (Reference)

Age BSA (m2)
Neonate (newborn) 0.25
Child of 2 years 0.3
Child of 2-4 years 0.5
Child of 5 years 0.75
Child of 9 years 1.07
Child of 10 years 1.14
Child of 12-13 years 1.33
Women 1.6
Male 1.9

Body mass index (BMI) (Reference)

Classification BMI (kg/m2)
Principal cut-off points Additional cut-off points
Underweight < 18.50 < 18.50
Severe thinness < 16.00 < 16.00
Moderate thinness 16.00—16.99 16.00—16.99
Mild thinness 17.00—18.49 17.00—18.49
Normal range 18.50—24.99 18.50—22.99
Overweight ≥ 25.00 ≥ 25.00
Pre-obese 25.00—29.99 25.00—27.49
Obese ≥ 30.00 ≥ 30.00
Obese class I 30.00—34.99 30.00—32.49
Obese class II 35.00—39.99 35.00—37.49
Obese class III ≥ 40.00 ≥ 40.00

User manual

In order to calculate body surface area, body mass index, lean body weight and ideal body weight please follow next steps:

  • In the field Body height enter your height
  • In the field Body weight enter your weight
  • In the field Age enter your age in years
  • Select your Sex and if you would like to calculate Body shape index than additionally enter your waist line in the field Waist line.
  • Press Calculate button.
  • Calculated parameters will appear in the table below according to your sex and age.

Please note that calculator is designed to simplify calculation of previously mentioned parameters and does not interpret your results. For interpretation of your results please consult your doctor or qualified specialist.

Information about calculated parameters

Body surface area (BSA) — in physiology and medicine, the body surface area is the measured or calculated surface area of a human body. For many clinical purposes BSA is a better indicator of Kouro than body weight because it is less affected by abnormal adipose mass. Nevertheless, there have been several important critiques of the use of BSA in determining the dosage of medications with a narrow therapeutic index, such as chemotherapy. Typically there is a 4–10 fold variation in drug clearance between individuals due to differing the activity of drug elimination processes related to genetic and environmental factors. This can lead to significant overdosing and underdosing (and increased risk of disease recurrence). It is also thought to be a distorting factor in Phase I and II trials that may result in potentially helpful medications being prematurely rejected.[1][2] The trend to personalized medicine is one approach to counter this weakness.

Body mass index (BMI) — is a value derived from the mass (weight) and height of an individual. The BMI is defined as the body mass divided by the square of the body height, and is universally expressed in units of kg/m2, resulting from mass in kilograms and height in metres. The BMI may also be determined using a table or chart which displays BMI as a function of mass and height using contour lines or colours for different BMI categories, and which may use other units of measurement (converted to metric units for the calculation). The BMI is an attempt to quantify the amount of tissue mass (muscle, fat, and bone) in an individual, and then categorize that person as underweight, normal weight, overweight, or obese based on that value. However, there is some debate about where on the BMI scale the dividing lines between categories should be placed.

Body shape index (BSI) — is a metric for assessing the health implications of a given human body height, mass and waist circumference. The inclusion of the latter is believed to make the BSI a better indicator of the health risks from excess weight than the standard Body Mass Index. The finding of the paper is that the BSI above 0.083 (when expressed in metric units) is indicative of a higher relative hazard. A value of 0.091 corresponds to the doubling of the relative hazard rate.

Lean body weight (LBW) — is a component of body composition, calculated by subtracting body fat weight from total body weight: total body weight is lean plus fat. The percentage of total body mass that is lean is usually not quoted – it would typically be 60–90%. Instead, the body fat percentage, which is the complement, is computed, and is typically 10–40%. The lean body mass (LBM) has been described as an index superior to total body weight for prescribing proper levels of medications and for assessing metabolic disorders, as body fat is less relevant for metabolism.

Ideal body weight (IBW) — was initially introduced by Devine in 1974 to allow estimation of drug clearances in obese patients; researchers have since shown that the metabolism of certain drugs relates more to IBW than total body weight. The term was based on the use of insurance data that demonstrated the relative mortality for males and females according to different height–weight combinations.

New in version 2.2

  • Added new formulas for calculation BSA, LBW, IBW and BSI. Added links on reliable sources.
  • Converter is optimized for mobile devices.