Body Surface Area Calculator (Mosteller, Du Bois)

Body surface area (BSA) calculator

Short answer

Body surface area (BSA) is the estimated area of your skin in square metres, worked out from height and weight. With Mosteller's formula, √(height cm × weight kg ÷ 3600), someone 180 cm (5 ft 11 in) and 80 kg has a BSA of 2.00 m²; the older Du Bois formula gives 2.00 m². It describes body size, not health.

Last reviewed 27 October 20262 published sourcesNot medical advice

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Body surface area (m², Mosteller) by height and weight
Height	55 kg	70 kg	85 kg	100 kg
155 cm (5 ft 1 in)	1.54	1.74	1.91	2.07
165 cm (5 ft 5 in)	1.59	1.79	1.97	2.14
175 cm (5 ft 9 in)	1.64	1.84	2.03	2.20
185 cm (6 ft 1 in)	1.68	1.90	2.09	2.27
195 cm (6 ft 5 in)	1.73	1.95	2.15	2.33

Height

55 kg

70 kg

85 kg

100 kg

155 cm (5 ft 1 in)

1.54

1.74

1.91

2.07

165 cm (5 ft 5 in)

1.59

1.79

1.97

2.14

175 cm (5 ft 9 in)

1.64

1.84

2.03

2.20

185 cm (6 ft 1 in)

1.68

1.90

2.09

2.27

195 cm (6 ft 5 in)

1.73

1.95

2.15

2.33

The two formulas

Mosteller: BSA = √(height × weight ÷ 3600), with height in centimetres and weight in kilograms. Mosteller proposed it as a simplified way to calculate surface area (Mosteller, 1987).

Du Bois: surface area (cm²) = weight^0.425 × height^0.725 × 71.84, which is 0.007184 × weight^0.425 × height^0.725 in square metres (Du Bois & Du Bois, 1916).

Other body measures

BSA measures size, not shape or composition. For those, try the BMI calculator, the waist-to-height ratio calculator and the body fat calculator.

Common questions

What is the formula for body surface area?

Mosteller's formula is BSA (m²) = √(height in cm × weight in kg ÷ 3600). The Du Bois formula is BSA (m²) = 0.007184 × weight^0.425 × height^0.725, with weight in kg and height in cm.

Which BSA formula should I use?

Mosteller published his in 1987 as a simpler way to get BSA with a calculator; the Du Bois formula dates from 1916. Across the heights and weights in the table below, they agree to within about 0.1 m², and closer for people of average build. If a clinician uses BSA for you, they will use the formula their service has chosen.

Is body surface area a measure of health?

No. It is a measure of size. It is used in medicine, for example to scale some doses, but it says nothing about body fat or fitness on its own.

Sources

Figures on this page were checked against these publications on 27 October 2026.

Mosteller RD. Simplified calculation of body-surface area. New England Journal of Medicine. 1987;317(17):1098. doi.org/10.1056/NEJM198710223171717

Du Bois D, Du Bois EF. Clinical calorimetry: tenth paper. A formula to estimate the approximate surface area if height and weight be known. Archives of Internal Medicine. 1916;17(6_2):863–871. doi.org/10.1001/archinte.1916.00080130010002

Body surface area (BSA) calculator