BMI And BSA Calculator

Calculation Formulas:

\[ BMI = \frac{W}{H^2} \] \[ BSA = \sqrt{\frac{W \times H}{3600}} \]

BMI (kg/m²):

BSA (m²):

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is BMI and BSA?

BMI (Body Mass Index): A measure of body fat based on height and weight that applies to adult men and women.

BSA (Body Surface Area): The total surface area of the human body, often used in medical calculations.

2. How Does the Calculator Work?

The calculator uses two formulas:

\[ BMI = \frac{Weight\ (kg)}{Height^2\ (m)} \] \[ BSA = \sqrt{\frac{Weight\ (kg) \times Height\ (cm)}{3600}} \]

Where:

BMI — Body Mass Index (kg/m²)
BSA — Body Surface Area (m²)
Weight — in kilograms (kg)
Height — in centimeters (cm) for BSA, converted to meters (m) for BMI

3. Importance of BMI and BSA

BMI: Used to screen for weight categories that may lead to health problems.

BSA: Used in medical fields to calculate drug dosages and medical indicators.

4. Using the Calculator

Tips: Enter weight in kilograms and height in centimeters. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is a healthy BMI range?
A: 18.5-24.9 is considered normal weight, below 18.5 is underweight, 25-29.9 is overweight, and 30+ is obese.

Q2: Why is BSA important in medicine?
A: Many physiological processes correlate better with BSA than body weight, making it useful for drug dosing.

Q3: What's the most common BSA formula?
A: The Mosteller formula (shown above) is widely used, though others like DuBois and Haycock exist.

Q4: How accurate are these calculations?
A: They provide good estimates but don't account for factors like muscle mass or body composition.

Q5: Can I use pounds and inches?
A: This calculator uses metric units. For imperial units, convert weight to kg (1 lb = 0.453592 kg) and height to cm (1 inch = 2.54 cm).