Body Surface Area Calculator
Calculate body surface area (BSA) in square meters with the Mosteller formula from height and weight.
- Average adult BSA
- ≈ 1.7 m²
Formula: BSA = √(height (cm) × weight (kg) ÷ 3600)
About Body Surface Area Calculator
Body Surface Area Calculator is a free online calculator that gives you an instant, accurate result as you type. Calculate body surface area (BSA) in square meters with the Mosteller formula from height and weight.
The calculation uses the standard formula BSA = √(height (cm) × weight (kg) ÷ 3600) and updates live with every change to the inputs. Everything runs client-side in your browser — fast, private, and free to use as often as you like.
The Mosteller formula, published in 1987, is the most widely used BSA equation in clinical practice because it can be computed mentally as √(height × weight ÷ 3600).
Results are estimates for educational purposes and not medical advice.
Frequently Asked Questions
Is Body Surface Area Calculator free to use?
Yes. Body Surface Area Calculator is completely free, with no sign-up, no downloads, and no usage limits. You can use it as many times as you like on any device with a web browser.
How accurate is this calculator?
The calculator applies the standard formula (BSA = √(height (cm) × weight (kg) ÷ 3600)) with full floating-point precision and rounds only the displayed result. For most practical purposes the results are exact.
Related Tools
BMR Calculator
Calculate your basal metabolic rate (BMR) with the Mifflin-St Jeor equation from weight, height, and age.
TDEE Calculator
Estimate total daily energy expenditure (TDEE) from weight, height, age, and an activity multiplier.
Calorie Deficit Calculator
See your daily calorie deficit and the estimated weekly weight loss it produces in pounds and kilograms.
Macro Calculator
Split your daily calories into grams of protein, carbs, and fat using adjustable macronutrient percentages.
Protein Intake Calculator
Calculate your recommended daily protein in grams from body weight and a grams-per-kilogram target.
Water Intake Calculator
Estimate how much water to drink per day in liters, cups, and fluid ounces based on your body weight.