Current for 2026•As of: July 2026

Body Surface Area Calculator calculate BSA via Mosteller.

Enter height and weight – get your body surface area in m² instantly

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Body Surface Area Calculator

Calculate body surface area using the Mosteller formula, in m².

100 cm220 cm
30 kg200 kg

Mosteller Formula

BSA = √(height (cm) × weight (kg) / 3600)

Body Surface Area (BSA)

2.00 m²

via Mosteller formula

Typical Reference Values

Adult woman (avg.)1.60 – 1.70 m²
Adult man (avg.)1.80 – 2.00 m²
Overall normal range1.50 – 2.20 m²

Medical notice: Body surface area is used in medicine, among other things, to dose chemotherapy drugs and calculate cardiac indices. This calculator provides an estimate using the Mosteller formula. Clinical dosing always requires calculation and review by a physician.

Body Surface Area (BSA): Formula and Medical Significance

Mosteller formula, normal values and clinical applications

The body surface area (BSA) is the total surface area of the human skin, expressed in square meters. It is an important medical parameter, since certain physiological measures and medication dosages are based on BSA. The most commonly used formula is the Mosteller formula (1987): BSA (m²) = √(height in cm × weight in kg / 3600).

The elegant reference example illustrates the formula perfectly: for a person 180 cm tall weighing 80 kg, √(180 × 80 / 3600) = √(14,400 / 3600) = √4 = 2.00 m². This round number makes the example an ideal memory aid for the Mosteller formula and shows that a normal-weight adult of average build can have a BSA of exactly 2 m².

Clinically, BSA is especially central in oncology. Many chemotherapy drugs are dosed in mg/m² BSA, because BSA predicts the pharmacological distribution volume and renal clearance better than body weight alone. A drug dosed at 50 mg/m² would be given as 90 mg to a patient with 1.8 m² BSA, and as 100 mg at 2.0 m². Choosing the correct dose can significantly affect treatment efficacy and toxicity.

Clinical Applications of BSA

Areas of Use in Medicine

Chemotherapy
Dosing in mg/m² BSA. More precise dosing than by body weight alone. Reduces the risk of over- or underdosing.
Cardiac Index
Cardiac output / BSA = cardiac index (normal 2.5–4.0 L/min/m²). Standardized comparison of heart performance independent of body size.
Kidney Function (GFR)
Glomerular filtration rate is normalized to 1.73 m² BSA – making measurements comparable between patients.
Burn Medicine
Calculating fluid requirements (Parkland formula) and estimating donor skin area for transplants.

Calculation Examples

180 cm, 80 kg (reference example)

180 cm, 80 kg (reference example)
ItemAmount
Height180 cm
Weight80 kg
180 × 80 / 3600 = 42.00 m² (√4)

165 cm, 60 kg

165 cm, 60 kg
ItemAmount
Height165 cm
Weight60 kg
165 × 60 / 3600 = 2.75≈ 1.66 m² (√2.75)

Frequently Asked Questions about Body Surface Area

Mosteller formula, normal values and medical significance

Body surface area (BSA) describes a person's total skin surface, expressed in square meters. In medicine it is used to dose certain drugs, especially chemotherapy agents, since these substances are dosed by body surface area rather than by body weight. BSA is also relevant for cardiac index (cardiac output per m² BSA) and renal clearance calculations. On average, adults have a BSA of about 1.7 m².

This calculator uses the Mosteller formula (1987): BSA (m²) = √(height (cm) × weight (kg) / 3600). The formula is simple to apply and gives good approximations for most adults. For a height of 180 cm and a weight of 80 kg: √(180 × 80 / 3600) = √(14,400 / 3600) = √4 = 2.00 m². Besides Mosteller, other formulas exist, such as DuBois (1916), Haycock (1978, for children) and Boyd (1935), which produce slightly different results.

The average body surface area for adults in medicine is 1.73 m² (the standard BSA per DuBois). Actual values vary depending on height and weight: women typically have 1.55–1.70 m², men 1.80–2.00 m². Very tall or heavy individuals can reach 2.2 m² or more. Children accordingly have lower BSA values – pediatric dosing therefore uses child-specific formulas (e.g. Haycock).

The most important clinical applications are: 1. Chemotherapy dosing: many cytostatic drugs such as doxorubicin, cisplatin or paclitaxel are dosed in mg/m² BSA. 2. Cardiac index: cardiac output (in L/min) divided by BSA gives the cardiac index (CI, normal 2.5–4.0 L/min/m²). 3. Glomerular filtration rate (GFR): standardized to BSA (mL/min/1.73 m²). 4. Burn medicine: calculating fluid requirements and estimating the area for skin grafts.

The Mosteller formula is considered a good compromise between accuracy and simplicity. A 2010 study showed that Mosteller agrees well with more elaborate reference formulas for normal-weight adults (deviation < 2%). For extreme over- or underweight, as well as for children and pregnant women, specialized formulas are more accurate. Clinical dosing decisions always require medical review – the calculator provides an estimate for orientation.

Important note

These calculations are for non-binding information only and do not replace professional tax advice. All information without guarantee. Learn more

Sources & calculation basis

Our calculations are based on the following official sources (as of: July 2026):

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