Which BSA formula is most accurate for drug dosing?

BSA is preferred over body weight for drug dosing because it better reflects metabolic mass, especially in patients with abnormal body composition. Using BSA helps avoid under- or overdosing in cases of obesity, malnutrition, or edema where weight alone is misleading.

Can I use these calculators for children and infants?

Yes, but you need a tool that supports formulas validated for pediatric use. The Mosteller formula works for children, but some calculators like Inch Calculator and MDApp allow you to select age-specific methods. Always confirm the formula range with your clinical guidelines before relying on the result.

Do I need to convert my height and weight to specific units?

Most of these calculators accept both metric and imperial units, so you can enter height in centimeters or feet/inches and weight in kilograms or pounds without converting first. Inch Calculator explicitly supports stones as well, which is uncommon among the free options.

Is BSA the same as BMI?

No, BSA and BMI measure different things. BMI uses height and weight to estimate body fat percentage and is screened for weight categories. BSA estimates the total surface area of the body and is used primarily for drug dosing, burn assessment, and physiological calculations. This calculator provides both metrics so you can see them side by side.

Medical & Clinical5 options compared

BSA Calculator – Body Surface Area

Calculates Body Surface Area (BSA) using the Mosteller formula, alongside calculating Body Mass Index (BMI). Users input basic measurements such as height and weight to generate the required clinical metrics. The tool provides these calculations in an easy-to-read format suitable for point-of-care medical assessments and includes citation context for reference. Healthcare professionals, students,...

Body measurements calculators

Editors’ Top PickBased on community votes

Inch Calculator

inchcalculator.com

This BSA calculator computes body surface area from height and weight with support for different units and optional s...

Open Inch Calculator Read review →

Other OptionsRanked by votes

02
02
Medscape Reference
reference.medscape.com
This calculator computes Body Surface Area using the Mosteller formula (alongside BMI) from user-entered height and w...
Open site View details
03
03
Calculator.net
calculator.net
This free Body Surface Area calculator estimates BSA from height and weight and returns results from multiple common ...
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04
04
Omni Calculator
omnicalculator.com
Use the BSA calculator to find a useful biometric that many healthcare professionals rely on for weight-related diagn...
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05
05
MDApp
mdapp.co
MDApp’s Body Surface Area tool estimates BSA using age, sex, height, and weight, with several selectable formulas. It...
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Side by side

BSA Calculator – Body Surface Area options compared

Tool	Best for	Strengths	Limitations
Inch Calculator inchcalculator.com	Users who want formula variety and unit flexibility	Supports Du Bois, Mosteller, Haycock and other formulas Works with metric and imperial units including stones	No clinical citation context built into the interface
Medscape Reference reference.medscape.com	Clinicians who need citation-ready output	Designed for point-of-care use with reference integration Includes BMI alongside BSA using the Mosteller formula	Requires user login to access the calculator
Calculator.net calculator.net	People who want to compare multiple formulas at once	Returns BSA results from several popular formulas simultaneously Includes reference values and usage context	Fewer unit options compared to Inch Calculator
Omni Calculator omnicalculator.com	Users who prefer a clean, modern interface with extra context	Explains why BSA matters in medicine and physiology Provides result sharing and embedding options	No mention of formula variety; likely uses a single default method
MDApp mdapp.co	Clinical and health-use scenarios needing age and sex inputs	Takes age and sex into account alongside height and weight Aimed at clinical scenarios with method explanations	Live page excerpt could not be fetched; limited visibility into features

Buyer's guide

How to choose a bsa calculator – body surface area

When picking a BSA calculator, the key decision is whether you need formula variety or clinical context. If you are a healthcare professional calculating drug dosages, choose a tool that shows the formula used and supports the units you work with daily. If you are a student or researcher, a calculator that lets you compare multiple formulas side by side helps you understand the differences between methods like Mosteller versus Du Bois. The tools that require a login, such as Medscape, are best reserved for situations where you need the output to be citation-ready for documentation or publication.

Questions

BSA Calculator – Body Surface Area FAQ

Which BSA formula is most accurate for drug dosing?: BSA is preferred over body weight for drug dosing because it better reflects metabolic mass, especially in patients with abnormal body composition. Using BSA helps avoid under- or overdosing in cases of obesity, malnutrition, or edema where weight alone is misleading.
Can I use these calculators for children and infants?: Yes, but you need a tool that supports formulas validated for pediatric use. The Mosteller formula works for children, but some calculators like Inch Calculator and MDApp allow you to select age-specific methods. Always confirm the formula range with your clinical guidelines before relying on the result.
Do I need to convert my height and weight to specific units?: Most of these calculators accept both metric and imperial units, so you can enter height in centimeters or feet/inches and weight in kilograms or pounds without converting first. Inch Calculator explicitly supports stones as well, which is uncommon among the free options.
Is BSA the same as BMI?: No, BSA and BMI measure different things. BMI uses height and weight to estimate body fat percentage and is screened for weight categories. BSA estimates the total surface area of the body and is used primarily for drug dosing, burn assessment, and physiological calculations. This calculator provides both metrics so you can see them side by side.

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