This free online body surface area calculator uses the Mosteller formula to estimate your BSA in square meters from your height and weight. BSA is widely used in clinical settings for drug dosing and organ function reference. This tool is provided for general, educational purposes only and is not a substitute for professional medical advice — always consult a healthcare provider for clinical decisions.
BSA is commonly used in medicine (e.g. drug dosing) as a general reference — consult a healthcare professional for clinical use.
How to Use the Body Surface Area Calculator
Enter your height in centimeters in the "Height (cm)" field.
Enter your weight in kilograms in the "Weight (kg)" field.
Click "Calculate BSA" to run the Mosteller formula.
Read your estimated body surface area in square meters (m²) in the result box above.
Frequently Asked Questions
It uses the Mosteller formula, BSA = square root of (height in cm × weight in kg / 3600), which gives the result in square meters (m²). This is one of the most common formulas used in clinical practice because of its simplicity and accuracy.
Enter height in centimeters (cm) and weight in kilograms (kg). If you have measurements in feet/inches or pounds, convert them to metric units before entering them here.
If the height or weight field is left blank, set to zero, or a negative number, the calculator displays an "Invalid input! Please enter a valid height and weight." message instead of a result.
Yes, this tool is completely free to use with no sign-up required. However, it is intended for general, educational purposes only and should not replace professional medical advice, diagnosis, or dosing decisions made by a qualified healthcare provider.