BSA
1.909 m^2
Formula
Mosteller
Note
Reference
Confirm clinical use with professionals.
Body & Fitness
Body Surface Area (BSA) Calculator
Calculate body surface area (BSA) using the Mosteller formula.
By Calculator Suite Pro Editorial Team | Last updated March 18, 2026
Use this estimate as body-metric context, then compare nearby fitness tools when one number needs more perspective.
Explore the Body & Fitness group for nearby calculators, examples, and guide links.
About this calculator
Body Surface Area (BSA) estimates the external surface area of the human body. It is commonly used in medical contexts such as medication dosing references and clinical assessments.
This calculator uses the Mosteller formula, which is widely used due to simplicity and reasonable accuracy for many adults.
BSA is a reference estimate and should not replace professional medical guidance for dosing or clinical decisions.
How the estimate is calculated
A short explanation of how the body or training inputs are turned into an estimate.
- Mosteller formula: BSA = sqrt((heightCm x weightKg) / 3600).
- Height and weight are combined into a scale factor and then square-rooted.
- The output unit is square meters (m^2).
- Different BSA formulas exist; Mosteller is popular because it is simple and practical.
Formula and interpretation limits
These are the formulas, assumptions, and screening limits used by this body or fitness calculator.
- Mosteller formula: BSA = sqrt((heightCm x weightKg) / 3600).
- Different BSA formulas exist; Mosteller is popular because it is simple and practical.
Where this estimate can help
Use these scenarios to decide whether the output is useful for tracking, planning, or a basic screen.
- Clinical reference calculations (with professional guidance)
- Education and learning BSA formulas
- Quick BSA estimate from height and weight
- Comparing changes as weight changes
- General health knowledge
- Research and academic exercises
- Medical dosing discussions (reference only)
- Fitness/health reporting context (reference only)
How to enter body metrics
- Enter your weight (kg).
- Enter your height (cm).
- Calculate to see BSA in square meters (m^2).
- Use the value as a reference estimate.
- If the value is used medically, confirm with a clinician.
Body-metric mistakes to avoid
Confusing results usually come from measurement errors, formula assumptions, or over-interpreting a single number.
- Entering height in meters instead of centimeters.
- Entering weight in pounds instead of kilograms.
- Assuming BSA is a precise measurement (it is an estimate).
- Using BSA directly for dosing without professional oversight.
- Comparing BSA across formulas and expecting identical values.
Interpretation tips
- Double-check units: kg and cm are required for this calculator.
- If you only have imperial units, convert them first for best accuracy.
- Use the result as a reference, not a medical instruction.
- For general body composition, use BMI, body fat percentage, and waist ratios.
Glossary
Quick definitions for body and fitness terms used on this page.
BSA
Body Surface Area: an estimate of the body's external surface area.
Mosteller formula
A common BSA formula: sqrt((heightCm x weightKg) / 3600).
Body-metric examples
Example
Input: Height: 175cm, Weight: 75kg
Output: BSA shown in m^2
Example
Input: Height: 165cm, Weight: 60kg
Output: BSA shown in m^2
Weight change
Input: Same height, higher weight
Output: BSA increases
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FAQ
What is BSA used for?
BSA is often used as a reference in clinical settings, including dosing guidelines and assessments.
Which formula does this use?
This calculator uses the Mosteller formula.
Is BSA the same as BMI?
No. BMI is weight-to-height ratio for screening. BSA estimates external surface area.
Is this accurate for everyone?
It is a practical estimate, but individuals vary. Different formulas can produce slightly different values.
Can I use this for children?
BSA can be used in pediatrics, but dosing and interpretation should be done by clinicians.
Do you store my inputs?
Most calculations run in your browser. No signup is required.
Body-metric references and update notes
Last updated: March 18, 2026
Reviewed by Calculator Suite Pro Editorial Team.
Use the output for general context; clinical or high-stakes decisions need professional confirmation.
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