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Body Surface Area

BSA tracks metabolic rate better than weight does, which is why drug doses are scaled to it. Du Bois is the classic formula; Mosteller is easier to compute and also widely used.

Your numbers

Body surface area

1.754m²

Result

1.752

Formula

Body surface area = 0.007184 × Height (cm)^0.725 × Weight (kg)^0.425

Actual dosing must follow the prescription — this figure is for understanding it, not for setting it.

What to enter

InputDefaultAccepted range
Height (cm)Height in centimetres; converted to metres inside the formula.17030 ~ 250
Weight (kg)The second weight you are comparing against.652 ~ 300

Step by step

FormulaBody surface area = 0.007184 × Height (cm)^0.725 × Weight (kg)^0.425
With the default numbersBody surface area = 0.007184 × 170^0.725 × 65^0.425
AnswerBody surface area = 1.754 m²

Quick reference table

Results when only Height (cm) changes and everything else stays put.

Height (cm)Body surface area (m²)Result (m²)
851.0611.239
1281.4281.52
1701.7541.752
2502.3192.125

What each result means

ResultAt default values
Body surface area (m²)Body surface area — used for drug and fluid dosing.1.754
Result (m²)What the formula gives back — the answer this page is for.1.752

Common mistakes

Actual dosing must follow the prescription — this figure is for understanding it, not for setting it.

Glossary

Height (cm)
Height in centimetres; converted to metres inside the formula.
Weight (kg)
The second weight you are comparing against.
Body surface area
Body surface area — used for drug and fluid dosing.
Result
What the formula gives back — the answer this page is for.

Frequently asked questions

Q. How is Body Surface Area calculated?

Body surface area = 0.007184 × Height (cm)^0.725 × Weight (kg)^0.425 — BSA tracks metabolic rate better than weight does, which is why drug doses are scaled to it. Du Bois is the classic formula; Mosteller is easier to compute and also widely used.

Q. Can you walk through an example?

With Height (cm) 170, Weight (kg) 65, the answer is Body surface area 1.754m².

Q. What do I need to enter?

Enter Height (cm), Weight (kg). The result recalculates as you type, and an empty box counts as zero.

Q. How much does the answer move if I change a number?

Changing only Height (cm) moves the answer to Height (cm) 85 → Body surface area (m²) 1.061 and Height (cm) 250 → Body surface area (m²) 2.319. The table below lays out five steps.

Q. How are the numbers rounded?

Money is shown to the nearest whole unit, percentages to one decimal place and everything else to two. What you see is rounded; the calculation itself carries the unrounded value forward.

Q. Anything to watch out for?

Actual dosing must follow the prescription — this figure is for understanding it, not for setting it.

Related calculators

These calculators help you understand health figures; they do not replace diagnosis or prescription. See a clinician if you have symptoms.