Body Surface Area Calculator
Calculate body surface area in m² used for medical dosing and burn area estimation.
Body Surface Area Calculator
Calculate body surface area in m² used for medical dosing and burn area estimation.
Body Mass Index (BMI)
ℹ️ Underweight < 18.5 | Normal 18.5–24.9 | Overweight 25–29.9 | Obese ≥ 30
Disclaimer
Results provided by this calculator are for informational and educational purposes only. They are based on the values you enter and standard formulas, and should not be considered financial, medical, legal, or professional advice. Always consult a qualified professional before making important decisions based on these results. Roughtools makes no warranties regarding the accuracy or completeness of these calculations for your specific situation.
Frequently Asked Questions
Pro Tips
BMI does not distinguish between muscle and fat — athletes routinely register as "overweight." Use BMI alongside waist circumference and body fat percentage for a complete picture.
Waist-to-height ratio (waist ÷ height) below 0.5 is a strong predictor of metabolic health — often more useful than BMI for assessing cardiovascular risk.
Asian populations have higher metabolic risk at lower BMI values. Some clinicians use BMI ≥23 as overweight for Asian adults, not the WHO standard of 25.
Track your BMI trend over months, not as a single snapshot. A consistent downward trend matters far more than hitting a specific number on any given day.
When to Use This Calculator
Calculate your BMI as part of your annual health self-assessment alongside blood pressure and cholesterol.
Find the BMI-normal weight range for your height to set a realistic, medically-recognised target weight.
Check whether BMI is in the healthy range before conceiving — optimal range reduces pregnancy complications.
Monitor BMI monthly during a training program — though note athletes may show high BMI despite low body fat.
Calculate your BMI in advance so you can have an informed conversation about your weight with your healthcare provider.
About the Body Surface Area Calculator
This body surface area calculator computes BSA in square meters using the four most clinically used formulas — Mosteller (most common), DuBois & DuBois (oldest), Haycock (pediatric use), and Gehan-George — from height and weight. BSA is used in clinical medicine to dose chemotherapy, calculate cardiac output, and set drug doses for medications where body weight alone is insufficient. Results are for reference only — all clinical dosing must be performed or verified by a licensed healthcare provider.
How to Use the Body Surface Area Calculator
- 1
Enter the patient's height in centimeters or feet/inches.
- 2
Enter the patient's weight in kilograms or pounds.
- 3
See BSA in m² calculated by all four major formulas.
- 4
Note the Mosteller formula result (most commonly used in clinical practice).
- 5
Always have a licensed healthcare provider verify and approve any clinical dose calculations.
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