Clinical Calculators

BSA (Body Surface Area)

Estimates body surface area from height and weight (Du Bois formula and Fujimoto formula)

Body surface area (Du Bois formula) 2 items left
Body surface area (Fujimoto formula) 3 items left

40 to 200
cm
0.5 to 150
kg
Age group (used for the Fujimoto formula)

The Fujimoto formula changes with age. It is not used for the Du Bois formula

Formula

  • Du Bois formula: BSA (m²) = 0.007184 × weight (kg) to the power 0.425 × height (cm) to the power 0.725
  • Fujimoto formula (6 years or older): BSA (m²) = 88.83 × weight (kg) to the power 0.444 × height (cm) to the power 0.663 ÷ 10000
  • Fujimoto formula (1 to 5 years): BSA (m²) = 381.89 × weight (kg) to the power 0.423 × height (cm) to the power 0.362 ÷ 10000
  • Fujimoto formula (under 1 year): BSA (m²) = 95.68 × weight (kg) to the power 0.473 × height (cm) to the power 0.655 ÷ 10000

Cautions

  • The formulas give different values (for example, 170 cm and 60 kg gives 1.69 m² by the Du Bois formula and 1.65 m² by the Fujimoto formula). When a dose is set from body surface area, use the formula your institution has agreed on.
  • The Du Bois formula was built from measurements on about 9 people. The Fujimoto formula was built from measurements on 201 Japanese people, and it covers newborns to older adults with 3 formulas divided by age.
  • The Fujimoto formula changes with age: under 1 year (age 0), 1 to 5 years, and 6 years or older. Without an age group the Fujimoto value is not shown (the Du Bois value is shown without one).
  • The Du Bois formula was built from 9 measured people, and for people with an extreme build the estimate can differ from the true body surface area (Verbraecken 2006 reported that in obese people the Du Bois and Mosteller formulas give different values).

References

  1. Du Bois D, Du Bois EF. A formula to estimate the approximate surface area if height and weight be known. Arch Intern Med. 1916;17(6):863-871. (p. 870, and the summary on p. 871) DOI: 10.1001/archinte.1916.00080130010002, https://zenodo.org/records/1423319[Original article]
  2. Fujimoto S, Watanabe T, Sakamoto A, Yukawa K, Morimoto K. Studies on the physical surface area of Japanese. Part 18: Calculation formulas in three stages over all ages (in Japanese). Jpn J Hyg. 1968;23(5):443-450. (Abstract, summary, Figures 2 to 4) https://www.jstage.jst.go.jp/article/jjh1946/23/5/23_5_443/_pdf[Original article]
  3. Burton RF. Estimating body surface area from mass and height: theory and the formula of Du Bois and Du Bois. Ann Hum Biol. 2008;35(2):170-184. (Abstract) PMID: 18428011, DOI: 10.1080/03014460801908439[Review article]
  4. Verbraecken J, Van de Heyning P, De Backer W, Van Gaal L. Body surface area in normal-weight, overweight, and obese adults. A comparison study. Metabolism. 2006;55(4):515-524. (Abstract) PMID: 16546483, DOI: 10.1016/j.metabol.2005.11.004[Review article]

Checked on: 2026-10-12

Disclaimer

This calculation is intended to support the judgment of healthcare professionals. Results are for reference only; decisions about diagnosis and treatment must be made by the responsible healthcare professional. The values you enter never leave your device.