Calculate body surface area with five medical formulas.
BSA = √(height in cm × weight in kg ÷ 3,600). A 175 cm, 70 kg adult has a BSA of about 1.84 m².
Body surface area (BSA) is the total area of the body's surface. Doctors use it to calculate doses of some medicines (notably chemotherapy), to interpret kidney function and to index heart measurements. This calculator gives BSA with five published formulas — Mosteller, DuBois & DuBois, Haycock, Gehan & George and Boyd.
The formulas agree closely for adults; Haycock and Gehan-George are often preferred for children. Never use this to work out your own medicine dose — your care team chooses the formula and rounding. Related: BMI Calculator and the GFR Calculator, which is indexed to 1.73 m² of body surface.
The calculator applies the standard published formulas step by step.
| Item | Value |
|---|---|
| Height | 175 cm (5 ft 8.9 in) |
| Weight | 70 kg (154.3 lb) |
| Average of the five formulas | 1.849 m² |
| Formula | BSA (m²) |
|---|---|
| Mosteller | 1.845 |
| DuBois & DuBois | 1.848 |
| Haycock | 1.847 |
| Gehan & George | 1.854 |
| Boyd | 1.851 |
| Height and weight | BSA |
|---|---|
| 150 cm, 55 kg | 1.51 m² |
| 165 cm, 65 kg | 1.73 m² |
| 175 cm, 70 kg | 1.84 m² |
| 180 cm, 85 kg | 2.06 m² |
| 190 cm, 100 kg | 2.3 m² |
The estimated total area of the skin, in square metres. An average adult has about 1.7–1.9 m².
Mosteller is the most common because it is simple and accurate; DuBois is the classic formula.
To dose drugs such as chemotherapy, to index cardiac output and to standardise kidney function (GFR per 1.73 m²).
The same formulas work, but Haycock and Gehan-George were designed with children in mind.
No. Doses are chosen and checked by your care team, who also apply rounding and safety limits.
About 1.9 m² for men and 1.6 m² for women, with 1.73 m² used as the standard adult reference.
It uses the published formula: Mosteller: BSA (m²) = √( height (cm) × weight (kg) ÷ 3,600 ) The full method and a worked example are shown on this page.
No. The calculator gives general estimates for information and education. It cannot diagnose or treat anything, so please speak to a doctor or qualified professional about your own health.
Yes. Choose centimetres or feet and inches for height, and kilograms, pounds or stone for weight; the results are converted for you.
No. Everything is calculated in your browser and nothing you enter is uploaded or saved.
