Estimate body surface area (BSA) using Mosteller, Du Bois, Haycock, Gehan & George, and Boyd formulas in metric or imperial units.
All calculations run locally on your browser. No height, weight, gender, or metabolic data is sent to external servers or logged. These estimates are designed for educational reference and initial evaluations.
Quickly evaluate standard metabolic demographics and sizing indices:
Enter your weight and stature dimensions to compute multi-formula clinical Body Surface Area indexes.
How different medical formulas calculate Body Surface Area based on weight and stature parameters.
| Formula Name | Mathematical Equation | Computed Result | Clinical Relevance & Context |
|---|---|---|---|
| Mosteller | BSA = √((Height in cm × Weight in kg) / 3600) | - | Published in 1987. Simple and easy to calculate. Now the most widely used formula in medicine. |
| Du Bois & Du Bois | BSA = 0.007184 × Height_cm^0.725 × Weight_kg^0.425 | - | Published in 1916. The historical standard model. Widely referenced in physiological and eGFR indices. |
| Haycock | BSA = 0.024265 × Height_cm^0.3964 × Weight_kg^0.5378 | - | Published in 1978. Preferred for pediatric calculations. Highly accurate for low birthweight newborns. |
| Gehan & George | BSA = 0.0235 × Height_cm^0.42246 × Weight_kg^0.51456 | - | Published in 1970. Provides a robust fit for populations with extreme heights and weights. |
| Boyd | BSA = 0.0003207 × Height_cm^0.3 × Weight_grams^(0.7285 - 0.0188 × log10(Weight_grams)) | - | Published in 1935. Highly complex formula that includes a logarithmic weight scaling term, ideal for pediatric and growth indexing. |
Why surface area index metrics are vital in medical assessments, renal clearances, and pharmacology.
In pharmacology, narrow-therapeutic-index medications (such as chemotherapy agents, immunotherapeutic drugs, and specific IV therapies) are dosed according to body surface area rather than body weight. This is because body water volume, blood volume, liver clearance pathways, and cardiac output correlate much more closely with BSA. Weight-only dosing can result in dangerous toxicity in obese patients or sub-therapeutic levels in extremely lean patients.
Glomerular Filtration Rate (GFR)—the primary measure of kidney health and filtration function—is standardly indexed to a standardized body surface area of **1.73 m²** (the normal average adult BSA). By dividing a patient's raw GFR values by their relative BSA index ratio, clinicians can directly compare kidney filtration capabilities across patients of widely differing body types.
The raw cardiac output (volume of blood pumped by the heart per minute) varies heavily based on body size. In intensive care medicine, doctors calculate the **Cardiac Index** by dividing cardiac output by the patient's BSA. A healthy Cardiac Index range is standardly 2.5 to 4.0 L/min/m². This adjusts outputs to body demands, allowing clinicians to diagnose heart failure or shock accurately regardless of patient height or mass.
Get personalized advice on fitness routines, diet plans, and understanding your health metrics better.
Topics this feature will cover:
Be first to access it when it launches.
We'll notify you the moment AI Advisor goes live. One email, no spam.
You're on the list!
Body Surface Area (BSA) is the total surface area of the human body, expressed in square meters (m²). It is widely used in healthcare as a more accurate indicator of metabolic activity and fluid requirements than body weight alone.
Chemotherapy drugs often have a very narrow therapeutic index, meaning the difference between an effective dose and a toxic dose is small. Dosing based on BSA helps standardize the concentration of the drug in the body, accounting for differences in blood volume and metabolic rates between individuals of varying heights and weights.
The Mosteller formula is the most popular due to its simplicity, while the Du Bois formula is the oldest and most historically standard. The Boyd formula is highly complex but preferred in pediatrics. Generally, all five formulas produce results within 1-2% of each other, and the average of these formulas is often used to minimize outliers.
The average BSA for an adult male is approximately 1.9 m², and for an adult female, it is approximately 1.6 m². The standard reference BSA used for indexing physiological parameters (like glomerular filtration rate or eGFR) is 1.73 m².
BSA formulas are mathematical models based on height and weight. They do not account for fluid retention (edema), severe dehydration, or body fat distribution. For extremely obese patients, some clinical guidelines recommend using an adjusted body weight rather than actual body weight in the equations.
Read our in-depth articles and guides related to this tool to help you make smarter decisions.
A BMI of 25 is "overweight" for a Western adult, but research shows South Asians carry significantly more body fat at the same BMI — and face higher metabolic risk. The WHO recognises lower BMI thresholds for Asians. Here is what the research says and why it matters.
Most Indians accept an EMI figure from their bank without questioning it. This guide explains exactly how Indian banks calculate EMI — the reducing balance method, how RBI repo rate changes flow through to your loan, and what you can do to pay off your home loan years early.
The answer to "how many calories per day" is not the same for everyone. Your TDEE — Total Daily Energy Expenditure — depends on your weight, height, age, sex, and activity level. Here is the exact formula and tables by goal.
Calculate your Body Mass Index (BMI) using height and weight. Supports metric and imperial systems, visual charts, and history tracking.
Estimate your body fat percentage, lean body mass, fat mass, and ideal ranges using body circumference measurements (U.S. Navy Method).
Calculate your daily calorie needs (TDEE/BMR) and recommended macronutrients based on activity levels and fitness goals.
Calculate your Basal Metabolic Rate (BMR) at rest using Mifflin-St Jeor and Harris-Benedict formulas.
Calculate your Total Daily Energy Expenditure (TDEE), representing the total calories you burn per day based on activity levels.
Calculate your ideal body weight range using Devine, Robinson, Miller, and Hamwi formulas. Adjust for body frame size and compare against your current weight.
Calculate your optimal daily protein requirements based on age, gender, weight, activity levels, and fitness goals. View meal splits and track protein food sources.
Calculate your Lean Body Mass (LBM) using Boer, James, Hume formulas or direct body fat percentage. Track muscle mass changes and composition stats.
Calculate your Body Mass Index (BMI) using height and weight. Supports metric and imperial systems, visual charts, and history tracking.
Estimate your body fat percentage, lean body mass, fat mass, and ideal ranges using body circumference measurements (U.S. Navy Method).
Calculate your daily calorie needs (TDEE/BMR) and recommended macronutrients based on activity levels and fitness goals.
Calculate your Basal Metabolic Rate (BMR) at rest using Mifflin-St Jeor and Harris-Benedict formulas.
See how systematic small savings grow into monumental long-term fortunes. Compute compound schedules instantly with zero registration required.
Convert any baseline salary metric instantly across multiple frequencies. Factor in working times, holidays, and unpaid vacations to reveal your effective time value with intelligent AI diagnostics.
Unleash the mathematical force of compounding. Model initial capital, recurring contributions, variable compound intervals, and analyze exponential progress instantly.
Easily add or subtract GST taxes with customizable percentages. Designed with large touch interfaces optimized specifically for mobile-first tax management.
Loved the Body Surface Area Calculator? Explore our suite of related utilities to boost your productivity even further.
