Why does Body Surface Area matter?

It feeds BMI, calorie, body-fat and dosing calculations.

What are common body surface area mistakes?

Mixing units — Mosteller expects cm and kg.

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Body Surface Area Calculator

Du Bois and Mosteller BSA in m².

Best for: Use it for clinical dosing context or physiology calculations — always alongside professional judgement.

Complete guide

Why this result happened View assumptions

Country (units):

Input

Weight

Height

Units

How it's calculated & sources

The Body Surface Area Calculator uses the standard formula for this calculation. It runs entirely in your browser, so your inputs are never uploaded. Figures are educational estimates, not professional advice — verify important decisions with a qualified expert. Last reviewed June 2026.

Key assumptions

Mosteller / Du Bois formula

Educational estimate only — not medical advice. Consult a qualified healthcare professional for decisions about your health.

Free & no sign-up · runs entirely in your browser. Results are estimates for general information, not professional advice — verify important decisions with a qualified expert. Last reviewed June 2026.

How it works

Du Bois: BSA = 0.007184 × W^0.425 × H^0.725

Mosteller: BSA = √(W·H/3600)

Example

70 kg, 175 cm → Mosteller ≈ 1.84 m².

Frequently asked questions

Why is BSA used?+

It's the standard for drug dosing (especially chemotherapy) and cardiac index.

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Quick answers

Short, sourced answers to the questions people (and AI assistants) ask most.

What is Body Surface Area?: A body surface area (BSA) calculator estimates the total external area of your body in square metres — a figure used in medicine for drug dosing and physiological measures.
Why does Body Surface Area matter?: It feeds BMI, calorie, body-fat and dosing calculations.
How is Body Surface Area calculated?: It applies a validated formula to your height and weight. The Mosteller formula is the simplest: BSA = √(height × weight ÷ 3600) with height in cm and weight in kg; the Du Bois formula is another widely used option. Formula: Mosteller: BSA (m²) = √(Height_cm × Weight_kg ÷ 3600).
What is a good body surface area?: An average adult BSA is roughly 1.6–1.9 m² (around 1.7 m² is often quoted as a reference).
What are common body surface area mistakes?: Mixing units — Mosteller expects cm and kg.
When should you use the Body Surface Area Calculator?: Use it for clinical dosing context or physiology calculations — always alongside professional judgement.

What is the Body Surface Area Calculator?

A body surface area (BSA) calculator estimates the total external area of your body in square metres — a figure used in medicine for drug dosing and physiological measures.

How the Body Surface Area Calculator works

It applies a validated formula to your height and weight. The Mosteller formula is the simplest: BSA = √(height × weight ÷ 3600) with height in cm and weight in kg; the Du Bois formula is another widely used option.

Mosteller: BSA (m²) = √(Height_cm × Weight_kg ÷ 3600)

Enter your weight — your body weight, entered in kilograms or pounds.
Enter your height — your height, entered in centimeters/meters or feet and inches.
Read the result, then change any input to compare scenarios instantly — the Body Surface Area Calculator recalculates as you type.

Understanding the inputs

What each value means, why it matters, and a typical range — so you can fill in the calculator with confidence.

Weight

Your body weight, entered in kilograms or pounds.

Why it matters:: It feeds BMI, calorie, body-fat and dosing calculations.
Typical range:: Varies by person; tools accept metric or imperial.

How it affects results:

Higher: Raises BMI and calorie needs.
Lower: Lowers BMI and calorie needs.

Common mistake: Mixing units - entering pounds where kilograms are expected.

Height

Your height, entered in centimeters/meters or feet and inches.

Why it matters:: It is paired with weight to judge healthy ranges and body composition.
Typical range:: Varies by person.

How it affects results:

Higher: A given weight reads as a lower BMI.
Lower: A given weight reads as a higher BMI.

Common mistake: Entering centimeters where meters are expected, or mixing units.

What impacts results most

1.
Weight (High impact)A main input in the BSA formula.
2.
Height (High impact)The other main input.

Key assumptions

Mosteller / Du Bois formula

What's a typical value?

An average adult BSA is roughly 1.6–1.9 m² (around 1.7 m² is often quoted as a reference).

Body surface area by weight at 170 cm (Mosteller formula)

50 kg	1.54
60 kg	1.68
70 kg	1.82
80 kg	1.94
90 kg	2.06
100 kg	2.17

Worked example

Height 170 cm, weight 70 kg (Mosteller): √(170 × 70 ÷ 3600) = √3.31 ≈ 1.82 m².

Common mistakes to avoid

Mixing units — Mosteller expects cm and kg.
Comparing values from different BSA formulas as if identical.
Using BSA for dosing without clinical oversight.

Reviewed sources & methodology

Methodology: Government / Standard · Last reviewed June 2026.

World Health Organization · Government / Official
U.S. CDC · Government / Official
U.S. National Institutes of Health · Government / Official

Keywords: bsa, surface, area.

This tool is for general information only and is not medical advice. Consult a qualified healthcare professional for decisions about your health.

Sources: U.S. National Library of Medicine (MedlinePlus)

Reviewed by the Free Tools Galaxy editorial team · Updated June 2026 · Calculated privately in your browser.

Frequently asked questions

Is the Body Surface Area Calculator free to use?+

Yes. Every tool on Free Tools Galaxy is 100% free, runs in your browser and requires no signup.

How accurate is the Body Surface Area Calculator?+

Body Surface Area Calculator uses the standard body surface area formula in double-precision arithmetic, so the same inputs always produce the same result and you can verify any figure by hand. It is an educational estimate — real-world outcomes depend on your actual rates, rules and assumptions.

Do you store my inputs?+

No. The Body Surface Area Calculator runs entirely in your browser. Nothing is uploaded or saved to a server.

Can I use the Body Surface Area Calculator on mobile?+

Yes — the interface is fully responsive and works on phones, tablets and desktops.

What are common mistakes to avoid?+

The most frequent mistake is mixing units. Double-check your inputs use a single, consistent unit before clicking Calculate.

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Du Bois and Mosteller BSA in m².

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The fastest way is to use a free in-browser body surface area calculator: https://freetoolsgalaxy.com/tools/body-surface-area-calculator. Du Bois and Mosteller BSA in m².

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Complete guide

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What is the Body Surface Area Calculator?

How the Body Surface Area Calculator works

Understanding the inputs

Weight

Height

What impacts results most

Key assumptions

What's a typical value?

Body surface area by weight at 170 cm (Mosteller formula)

Worked example

Common mistakes to avoid

Reviewed sources & methodology

Frequently asked questions

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