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BSA Calculator

The BSA Calculator is an optimized, single-formula utility engineered for rapid computation of human Body Surface Area using the standard Mosteller ra

Health & Fitness
cm
Standing height in centimetres
kg
Current body mass in kilograms
Formula & Methodology
BSA (m²) = √([Height (cm) × Weight (kg)] ÷ 3,600)

Published by Dr. R.D. Mosteller in the New England Journal of Medicine in 1987, this simplified formula calculates body surface area by taking the square root of the product of height in centimetres and weight in kilograms divided by 3,600. It provides a reliable mathematical approximation that eliminates the need for complex exponential calculators.

Body Surface Area (Mosteller Formula)

1.84 m² m²

Overview

The BSA Calculator is an optimized, single-formula utility engineered for rapid computation of human Body Surface Area using the standard Mosteller radical equation. By requiring minimal inputs—only height in centimetres and weight in kilograms—it delivers an instantaneous, clean calculation for academic and physiological study.

Educational & Non-Clinical Disclaimer: This calculator is designed solely for rapid educational reference. It is strictly NOT intended for clinical medical use, drug dosing, chemotherapy planning, or patient treatment. Consult qualified healthcare professionals for clinical calculations.

Worked Examples

Standard Adult Example: 175 cm and 70 kg

Height = 175 cm, Weight = 70 kg.

  1. Multiply height by weight: 175 × 70 = 12,250.
  2. Divide product by 3,600: 12,250 ÷ 3,600 = 3.402777...
  3. Take the square root: √(3.402777...) = 1.84466... m².
  4. Round to two decimal places: 1.84 m².
Final Answer: 1.84 m²

Tall Adult Example: 190 cm and 85 kg

Height = 190 cm, Weight = 85 kg.

  1. Multiply height by weight: 190 × 85 = 16,150.
  2. Divide by 3,600: 16,150 ÷ 3,600 = 4.486111...
  3. Take square root: √(4.486111...) = 2.1180... m².
  4. Round to two decimal places: 2.12 m².
Final Answer: 2.12 m²

Petite Adult Example: 155 cm and 50 kg

Height = 155 cm, Weight = 50 kg.

  1. Product: 155 × 50 = 7,750.
  2. Divide by 3,600: 7,750 ÷ 3,600 = 2.15277...
  3. Square root: √(2.15277...) = 1.4672... m².
  4. Round to two decimal places: 1.47 m².
Final Answer: 1.47 m²

How to Use This Calculator

  1. Enter standing height in centimetres.
  2. Enter body weight in kilograms.
  3. Instantly view your calculated Body Surface Area in square metres (m²).
  4. Review the mathematical breakdown and formula details.

Frequently Asked Questions

Why does this tool use the Mosteller formula specifically?
The Mosteller formula is the most widely adopted standard across modern medical literature, academic software, and clinical trials due to its elegant simplicity, fast calculation, and empirical agreement with classical exponential formulas like Du Bois.
How is this page different from the Body Surface Area Calculator page?
This BSA Calculator is a streamlined single-formula utility designed for rapid execution with minimal inputs. In contrast, our full Body Surface Area Calculator provides an in-depth explainer comparing five distinct equations (Mosteller, Du Bois, Haycock, Boyd, Gehan) with historical context and imperial conversion options.
What is the average human body surface area?
In adult human populations, average BSA is approximately 1.9 m² for men and 1.6 m² for women. However, individual values vary from below 1.4 m² in petite adults to over 2.4 m² in large or muscular individuals.
Can this formula be used for children?
While the Mosteller formula is frequently used across all ages, pediatric specialists often cross-check with the Haycock formula for infants and small children. Note that this website tool is educational only and not for pediatric clinical dosing.
Is BSA more accurate than BMI for health assessment?
BSA and BMI serve different purposes. BMI is a population screening ratio for weight categories, whereas BSA represents absolute surface area used to calculate metabolic scaling, kidney clearance, and cardiac index.

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Reviewed & Authored by: OnlineConvers Health & Quantitative Science Editorial Team · Last Updated: 2026-10-07
Calculates Body Surface Area exclusively using the Mosteller (1987) equation: BSA (m²) = √([Height (cm) × Weight (kg)] / 3600). Inputs are strictly validated to be positive real numbers. Results are rounded to two decimal places, matching international scientific publication standards.
Citations: Simplified calculation of body-surface area (New England Journal of Medicine (Mosteller RD, 1987)) · Validity of the Mosteller formula for body surface area estimation (Annals of Pharmacotherapy (2002))