Body Surface Area Calculator

Calculate your body surface area using the medical standard Mosteller and Du Bois formulas

Health

Medical

Body Metrics

Units

Measurements

Height (cm)

Weight (kg)

Average BSA by Age and Sex

Age Group	Male (m²)	Female (m²)
Newborn	0.22	0.22
2 years	0.55	0.55
5 years	0.75	0.75
10 years	1.12	1.09
15 years	1.63	1.5
Adult (20–79)	1.91	1.69

Reference values based on average height and weight for each age group. Individual BSA varies with actual body measurements.

About This Tool

This body surface area calculator computes your BSA using two standard medical formulas side by side — the Mosteller formula (1987) and the Du Bois formula (1916). Both are widely used in clinical practice for drug dosing, fluid management, and metabolic assessments.

BSA is one of several important body metrics. For a complete picture of your body composition, check out our Body Fat Percentage Calculator, Ideal Body Weight Calculator, and Lean Body Mass Calculator.

All processing happens entirely in your browser — no personal measurements are sent to any server. Your health data stays private.

Frequently Asked Questions (FAQ)

What is Body Surface Area (BSA)?

Body surface area is the total surface area of the human body. It is used extensively in medicine for determining drug dosages (especially chemotherapy), calculating cardiac output, and estimating fluid requirements. BSA is considered a more accurate physiological measure than body weight alone because it correlates with metabolic rate.

Which formula is more accurate — Mosteller or Du Bois?

Both formulas are widely used and provide very similar results for adults. The Mosteller formula is simpler (using a square root) and is the most commonly used in modern medicine. The Du Bois formula is the classic standard from 1916 and tends to give slightly higher values. For most clinical purposes, Mosteller is preferred due to its simplicity. For tracking body composition alongside BSA, see our Body Fat Percentage Calculator.

How do I use BSA for medication dosing?

Many chemotherapy drugs are dosed based on BSA (mg/m²). Your doctor or pharmacist will multiply the recommended dose per m² by your BSA to determine the correct dosage. Never self-dose based on BSA — always consult a healthcare professional.

What is a normal BSA value?

The average BSA for adult men is approximately 1.9 m² and for adult women approximately 1.7 m². BSA increases with body weight and height. Values typically range from about 1.5 to 2.5 m² for adults. For calculating other body metrics, try our Ideal Body Weight Calculator or Lean Body Mass Calculator.

Is my data safe?

Yes. All calculations happen entirely in your browser — no personal measurements are ever sent to any server. Your health data remains completely private at all times.

Can I use imperial units?

Yes. Toggle the units selector to switch between metric (kg/cm) and imperial (lb/in). The calculations internally convert everything to metric before applying the formulas and display results in m².

Related Tools

🔥

Calories Burned Calculator

Estimate calories burned for any activity using MET values. Enter your weight, choose an activity, and set the duration to see calories burned and food equivalents.

📧

Email List Value Calculator

Calculate the monetary value of your email list based on subscriber count, open rate, click rate, conversion rate, and commission. Essential for email marketers.

🫁

VO₂ Max Estimator

Estimate your VO₂ max using multiple methods: resting heart rate, Cooper 12-minute run, 1.5-mile run, and Rockport walk test. Compare results with age and sex norms.

🔗

URL Slug Generator

Generate clean, SEO-friendly URL slugs from text with customizable options for separators, case, and special characters.