Calculate total surface area for clinical and physiological assessments.
Mosteller Formula: m²
Du Bois Formula: m²
Haycock Formula: m²
What is Body Surface Area (BSA)?
Body Surface Area (BSA) is the measured or calculated surface of a human body. In clinical medicine, BSA is often considered a more accurate indicator of metabolic mass than body weight because it is less affected by abnormal adipose tissue. It is primarily used to calculate dosages for chemotherapy, corticosteroids, and other drugs with a narrow therapeutic index.
Common Formulas Used
Our calculator provides results using the three most clinically validated formulas:
Mosteller Formula: The simplest and most commonly used: √([Height(cm) × Weight(kg)] / 3600)
Du Bois Formula: Traditionally used in metabolic studies: 0.007184 × Height(cm)^0.725 × Weight(kg)^0.425
Haycock Formula: Often preferred for pediatric patients: 0.024265 × Height(cm)^0.3964 × Weight(kg)^0.5378
Typical BSA Ranges
Category
Average BSA (m²)
Neonate (Newborn)
0.25 m²
Child (9 years)
1.07 m²
Adult Woman
1.60 m²
Adult Man
1.90 m²
Why BSA Matters in Medicine
Clinicians use BSA for various critical calculations, including:
Chemotherapy Dosing: Most cytotoxic drugs are dosed per square meter of BSA to minimize toxicity.
Cardiac Index: Relates the cardiac output to the size of the individual.
Renal Function: Glomerular Filtration Rate (GFR) is often normalized to a standard BSA of 1.73 m².
Example Calculation
For an adult male who is 180 cm tall and weighs 85 kg:
Mosteller: √((180 * 85) / 3600) = 2.06 m²
Du Bois: 0.007184 * (180^0.725) * (85^0.425) = 2.05 m²
function calculateBSA() {
var height = parseFloat(document.getElementById('bsa_height').value);
var weight = parseFloat(document.getElementById('bsa_weight').value);
var resultBox = document.getElementById('bsa_result_box');
if (isNaN(height) || isNaN(weight) || height <= 0 || weight <= 0) {
alert('Please enter valid positive numbers for height and weight.');
resultBox.style.display = 'none';
return;
}
// Mosteller Formula: sqrt( (h*w) / 3600 )
var mosteller = Math.sqrt((height * weight) / 3600);
// Du Bois Formula: 0.007184 * h^0.725 * w^0.425
var dubois = 0.007184 * Math.pow(height, 0.725) * Math.pow(weight, 0.425);
// Haycock Formula: 0.024265 * h^0.3964 * w^0.5378
var haycock = 0.024265 * Math.pow(height, 0.3964) * Math.pow(weight, 0.5378);
// Display results
document.getElementById('res_mosteller').innerHTML = mosteller.toFixed(3);
document.getElementById('res_dubois').innerHTML = dubois.toFixed(3);
document.getElementById('res_haycock').innerHTML = haycock.toFixed(3);
resultBox.style.display = 'block';
// Smooth scroll to result
resultBox.scrollIntoView({ behavior: 'smooth', block: 'nearest' });
}