# Body Surface Area (BSA) Calculator

## Definition

- Body surface area
- The surface area of the body expressed in square meters (m
^{2}). It may be calculated when the height and weight of a subject are known by using a standard formula. BSA is an important measure in calculating pediatric dosages, in the management of burn patients, and the determining radiation dosages.

## DuBois & DuBois BSA Formula

0.007184 × H^{0.725} × W^{0.425}

- H = Height in centimeters (cm)
- W = Weight in kilograms (kg)

Among the various BSA formulae used in western countries, the DuBois formula is the standard … The other western formulae showed larger discrepancies than the Fujimoto and DuBois formulae.

## Gehan & George BSA Formula

0.0235 × H^{0.42246} × W^{0.51456}

- H = Height in centimeters (cm)
- W = Weight in kilograms (kg)

## Boyd BSA Formula

0.0003207 × H^{0.3} × W^{0.7285 - (0.0188 × log10W)}

- H = Height in centimeters (cm)
- W = Weight in kilograms (grams)

## Mosteller BSA Formula

$\sqrt{\frac{H\times W}{\mathrm{3600}}}$

- H = Height in centimeters (cm)
- W = Weight in kilograms (grams)

## Haycock BSA Formula

0.024265 × H^{0.3964} × W^{0.5378}

- H = Height in centimeters (cm)
- W = Weight in kilograms (kg)

## Fujimoto BSA Formula

0.008883 × H^{0.663} × W^{0.444}

- H = Height in centimeters (cm)
- W = Weight in kilograms (kg)

## Example

The doctor has ordered an antibiotic on 11 y/o Billy. The average adult dose is 250 mg. In order to calculate pediatric doses you must first determine Billy's body surface area (BSA). Billy is 157.5 cm in height and weighs 45 kg. Use the DuBois & DuBois formula.

- Weight = 45 kg
- Height = 157.5 cm

Use the exponent key on your computer's or smartphone's calculator in scientific mode in order to use the formula (e.g., `X ^{y}`).

- Enter 45. Press the
`X`key on your calculator. Enter 0.425^{y} - Press the multiply button
`×` - Enter 157.5. Press the
`X`key on your calculator. Enter 0.725^{y} - Press the multiply button
`×` - Enter 0.007184. Press the = button
`=`

Billy's BSA is calculated as 1.42 m^{2}.

## References

- Gehan, E. A., & George, S. L. (1970). Estimation of human body surface area from height and weight. Cancer chemotherapy reports, 54(4), 225.
- Kouno, T., Katsumata, N., Mukai, H., Ando, M., & Watanabe, T. (2003). Standardization of the body surface area (BSA) formula to calculate the dose of anticancer agents in Japan. Japanese journal of clinical oncology, 33(6), 309-313.
- Current, J. (1997). A Linear Equation For Estimating The Body Surface Area In. Anesthesiology, 2(2).
- Venes, D. (1989). Taber's cyclopedic medical dictionary. FA Davis.
- Redlarski, G., Palkowski, A., & Krawczuk, M. (2016). Body surface area formulae: an alarming ambiguity. Scientific reports, 6, 27966.