Body Surface Area Calculator: Accurate BSA Measurement for Medical Dosing
A Body Surface Area (BSA) calculator lets you enter height and weight, converts any units, then applies Mosteller, DuBois, or Haycock formulas to give you an area in m²—vital because chemotherapy doses are prescribed per square metre and the average adult BSA is ≈ 1.7 m² (Mosteller, 1987).
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How to use the tool
1 Enter height
Type a value, e.g., 182 or 63.
Select a unit—cm, m, in, ft.
2 Enter weight
Type a value, e.g., 85 or 120.
Choose kg or lb.
3 Pick a formula (optional)
Mosteller – fast, widely accepted.
DuBois & DuBois – historical clinical standard.
Haycock – reliable across ages.
4 Press “Calculate”
The result appears in m² together with the formula name.
Chemo drugs are dosed in mg / m² (NCI Drug Dictionary, cancer.gov).
Burns > 20 % TBSA need fluid resuscitation (American Burn Association Guidelines, 2019).
Mosteller error band ±2 % versus 3-D scans (Yu et al., 2020, J Med Syst).
FAQ
What is Body Surface Area?
BSA is the total external area of your body, reported in m²; it scales physiological processes better than weight alone (Mosteller, 1987).
How does the calculator convert units?
It multiplies feet by 30.48, inches by 2.54, and pounds by 0.453592 to obtain centimetres and kilograms (NIST Handbook 44, 2023).
Which formula should I choose?
Most clinicians pick Mosteller for speed; DuBois offers historical continuity; Haycock gives near-identical results in children (Haycock et al., 1978).
What inputs do I need?
You only enter height and weight with matching units; the tool handles all conversions and exponents automatically.
How is BSA used in chemotherapy?
Doses are prescribed as mg / m² to balance efficacy with toxicity; for example, 1.75 m² × 100 mg / m² = 175 mg total (NCI Protocol Templates, 2022).
How accurate are the formulas?
Mosteller stays within ±2 % of 3-D body-scan measurements (Yu et al., 2020) while DuBois varies ±5 % at size extremes (DuBois, 1916).
Can children use this tool?
Yes; Haycock was validated from premature infants to 18-year-olds, quote: “extends accuracy across paediatric ranges” (Haycock et al., 1978).
How is BSA different from BMI?
BMI divides weight by height² to flag under- or overweight; BSA multiplies height by weight to normalise metabolic load, serving dosing and thermoregulation studies (WHO Obesity Report, 2022).
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