BSA Calculator — Body Surface Area (Mosteller, DuBois, Haycock)

Calculate body surface area using Mosteller, DuBois, and Haycock formulas side by side. Includes an optional mg/m² dosing reference field.

July 2, 2026 Updated August 14, 2026

Units

Height (cm)

Weight (kg)

Dose per m² (optional — e.g. for a mg/m² dosing reference)

Uses the Mosteller BSA value. For reference only — always follow your prescriber's exact dosing calculation.

Mosteller (Standard/Most Common)

1.818 m²

DuBois & DuBois

1.810 m²

Haycock

1.826 m²

Mosteller: √((height cm × weight kg) ÷ 3600). DuBois: 0.007184 × height^0.725 × weight^0.425. Haycock: 0.024265 × height^0.3964 × weight^0.5378. Formulas typically agree within 1-2% for average adult body sizes but can diverge more at pediatric or larger body sizes. This tool is for reference and educational purposes — actual medication dosing must be calculated and verified by a qualified healthcare provider, not derived solely from this calculator.

94% found this helpful

Reference Values

Last verified: Jul 2, 2026

Category	Range	What It Means	Status
Mosteller Formula ★	√((height cm × weight kg) ÷ 3600)	The most widely used formula in clinical practice — simple, well-validated, and the preferred standard for chemotherapy dosing.	★ Best
DuBois & DuBois Formula	0.007184 × height^0.725 × weight^0.425	The original 1916 formula, still permitted at many chemotherapy sites as long as it doesn't produce more than a 10% dosing difference from Mosteller.	Good
Haycock Formula	0.024265 × height^0.3964 × weight^0.5378	Commonly preferred in pediatric settings — performs well across smaller body sizes where adult-derived formulas can be less accurate.	Good
Typical Adult Range	~1.6 m² (average female) to ~1.9 m² (average male)	Average adult BSA is often cited around 1.7 m² overall — individual results vary substantially with height and weight.	Okay

Source: Mosteller RD (1987) NEJM; Du Bois D & Du Bois EF (1916) Arch Intern Med; Haycock GB et al. (1978) J Pediatr — standard clinical BSA formulas

Worked Examples

Average Adult — 170 cm, 70 kg

Height: 170 cm
Weight: 70 kg

Mosteller: 1.818 m² · DuBois: 1.810 m² · Haycock: 1.826 m²

All three formulas agree closely (within 1%) for typical adult proportions — this is the normal case where formula choice matters least.

Child — 150 cm, 25 kg

Height: 150 cm
Weight: 25 kg

Mosteller: 1.021 m² · DuBois: 1.067 m² · Haycock: 0.999 m²

The formulas diverge more at smaller body sizes — a roughly 7% spread between DuBois and Haycock here, which is why Haycock is often preferred in pediatric dosing.

Larger Adult — 180 cm, 95 kg

Height: 180 cm
Weight: 95 kg

Mosteller: 2.179 m² · DuBois: 2.148 m² · Haycock: 2.201 m²

Above the typical 1.6–1.9 m² adult range — at higher body sizes, formula choice can shift a chemotherapy dose calculation by a meaningful amount, which is why sites cap acceptable formula disagreement at 10%.

How to Use This Calculator

1

Choose units and enter height and weight

Metric (cm/kg) or imperial (ft-in/lb) — whichever matches your available measurements.
2

Read all three formula results at once

Mosteller, DuBois & DuBois, and Haycock are calculated simultaneously so you can compare them directly.
3

Optionally add a dose-per-m² reference value

See a reference total dose based on the Mosteller BSA value — for educational reference only, not a substitute for prescriber-calculated dosing.

What Each Value Means

Body Surface Area (BSA) (m²): An estimate of the total surface area of the human body, calculated from height and weight, used to scale medication doses and other clinical measures more precisely than body weight alone.
Mosteller Formula (m²): BSA = √((height cm × weight kg) ÷ 3600). The most commonly used clinical BSA formula, preferred for its simplicity and validation in chemotherapy dosing.
DuBois & DuBois Formula (m²): BSA = 0.007184 × height^0.725 × weight^0.425. The original 1916 BSA formula, still in clinical use today.
Haycock Formula (m²): BSA = 0.024265 × height^0.3964 × weight^0.5378. Often preferred in pediatric dosing calculations.

Frequently Asked Questions

What is the Mosteller formula for body surface area?

BSA (m²) = √((Height in cm × Weight in kg) ÷ 3600). It's the most widely used BSA formula in clinical practice today because it's simple to calculate and well-validated — it's the preferred standard for chemotherapy dosing at most institutions.

What is the difference between Mosteller, DuBois, and Haycock formulas?

Mosteller is the simplest and most commonly used, especially for chemotherapy dosing. DuBois & DuBois (1916) is the original BSA formula, still permitted at many sites as long as it doesn't produce more than a 10% dosing difference from Mosteller. Haycock is favored in pediatric settings because it tends to perform better across smaller body sizes, where the other formulas can diverge more from measured values.

Why do BSA formulas give slightly different results?

Each formula was derived from a different (and relatively small, by modern standards) study population using slightly different mathematical relationships between height, weight, and surface area. They typically agree within 1-2% for average adult body sizes, but diverge more at pediatric or larger body sizes — this calculator shows all three simultaneously so you can see the actual spread for your specific measurements.

What is BSA used for in medicine?

BSA is used to normalize drug dosing (especially chemotherapy, expressed as mg/m²), calculate cardiac index (cardiac output divided by BSA), assess burn severity as a percentage of total body surface area, and various other body-size-adjusted clinical calculations where total body weight alone doesn't scale appropriately with drug distribution or physiological measures.

What is a normal BSA range for adults?

Average adult BSA is commonly cited around 1.7 m² overall, with typical ranges of roughly 1.6 m² for an average adult female and 1.9 m² for an average adult male — but BSA scales with both height and weight, so the actual range across individuals is considerably wider than these population averages suggest.

References & Sources

[1]
FDA — Labeling for Dosing Based on Weight or Body Surface Area (opens in new tab)
Supports: Evidence used for bsa glossary: mosteller, dubois, haycock & dosing terms, including related formulas, definitions, or reference values.

Verified Aug 14, 2026
[2]
NIH PMC — Body Surface Area Capping May Not Improve Cytotoxic Drug Safety (opens in new tab)
Supports: Evidence used for bsa glossary: mosteller, dubois, haycock & dosing terms, including related formulas, definitions, or reference values.

Verified Aug 14, 2026
[3]
NIH PMC — Evaluation of Nine Formulas for Estimating Pediatric Body Surface Area (opens in new tab)
Supports: Evidence used for bsa for pediatric dosing: why formula choice matters more in children, including related formulas, definitions, or reference values.

Verified Aug 14, 2026