Body Surface Area Calculator (BSA)

Body surface area calculator: BSA in m² from height and weight (Mosteller formula), with the Du Bois estimate for comparison.

BSA = √H · W3600

How to use this calculator

  1. Choose the quantity you want under “Solve for”.
  2. Type the known values and pick their units: any combination works.
  3. The result updates as you type. Open “Show the steps” to see the substitution.

BSA is used to dose some medicines and to index measurements such as cardiac output. Average adult BSA is about 1.7–1.9 m².

For general information only; it does not replace advice from a doctor or other health professional.

Formula

BSA = √H · W3600

SymbolQuantityUnits
WWeightkg, g, mg, µg, t, lb, oz, st, US ton, ct, Da
HHeightm, km, cm, mm, µm, nm, pm, Å, in, ft, yd, mi, nmi, au, ly
BSABody surface aream², km², cm², mm², ha, ft², in², yd², ac, mi²

Constants used: Mosteller formula · H in cm, W in kg

Worked example

Given: W = 70 kg · H = 175 cm

BSA = √H W3600

Result: BSA = 1.84466 m²

Body surface area for different values of Weight

W · WeightBSA · Body surface area
56 kg1.6499 m²
63 kg1.75 m²
70 kg1.8447 m²
77 kg1.9347 m²
84 kg2.0207 m²
91 kg2.1032 m²

Other values as in the worked example.

Frequently asked questions

70 kg and 175 cm?

BSA ≈ 1.84 m².

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