Kropsoverflade kalkulator – BSA-formel
Calculate your Body Surface Area (BSA) using the Mosteller, DuBois, or Haycock formula. Used for medication dosing and burn treatment.
Slik bruker du denne kalkulatoren
- Skriv inn Weight (kg)
- Skriv inn Height (cm)
- Skriv inn Formula (0=Mosteller, 1=DuBois, 2=Haycock)
- Klikk på Beregn-knappen
- Les resultatet som vises under kalkulatoren
Body Surface Area Formulas
Body Surface Area (BSA) estimates the total surface area of the human body, used primarily in medicine for calculating drug doses (especially chemotherapy) and assessing burn severity.
Three main formulas are used:
- Mosteller (1987): BSA = √(height × weight / 3600) — simplest and most widely used
- DuBois & DuBois (1916): BSA = 0.007184 × weight^0.425 × height^0.725 — the original formula
- Haycock (1978): BSA = 0.024265 × weight^0.5378 × height^0.3964 — optimized for children
The average adult BSA is approximately 1.7 m² (range: 1.5–2.2 m²).
Clinical Uses of BSA
BSA is the preferred metric for medical dosing because it correlates better with many physiological parameters than body weight alone:
- Chemotherapy: Most cancer drugs are dosed in mg/m² BSA
- Cardiac output: Indexed to BSA for comparison across patients
- Burns: The Rule of Nines estimates BSA affected to guide fluid resuscitation
- Kidney function: GFR is normalized to 1.73 m² BSA
BSA vs BMI
BSA and BMI (Body Mass Index) measure different things:
- BMI: Weight-to-height ratio, used for population-level obesity screening. Simple but ignores body composition.
- BSA: Estimated total skin surface, used for clinical drug dosing. More complex but not a health/obesity indicator.
Neither metric alone tells you everything about health. They serve different clinical purposes and should be interpreted in context.
Referanseverdier for Kroppsoverflate
Typiske BSA-verdier etter alder og størrelse.
| Pasienttype | BSA (Mosteller formel) |
|---|---|
| Newborn (3 kg, 50 cm) | 0.21 m² |
| Infant 6 months (7 kg, 65 cm) | 0.36 m² |
| Child 2 years (12 kg, 87 cm) | 0.53 m² |
| Child 5 years (18 kg, 109 cm) | 0.73 m² |
| Child 10 years (32 kg, 138 cm) | 1.06 m² |
| Adolescent 15 years (56 kg, 163 cm) | 1.58 m² |
| Adult man (70 kg, 178 cm) | 1.85 m² |
| Adult woman (60 kg, 165 cm) | 1.66 m² |
| Tall adult (90 kg, 190 cm) | 2.10 m² |
Sist oppdatert: March 2026
Frequently Asked Questions
What is a normal BSA for an adult?
Average adult BSA is approximately 1.7 m² for women and 1.9 m² for men, but healthy BSA ranges from about 1.4 m² to 2.2 m² depending on height and weight. The 'standard reference' often used in medical calculations is 1.73 m².
Why is BSA used for chemotherapy dosing instead of body weight?
BSA correlates better with kidney clearance, liver metabolism, and cardiac output than body weight alone, making it a more reliable basis for calculating drug doses that balance efficacy and toxicity. However, its superiority over weight-based dosing is debated in current oncology literature.
Which BSA formula should I use?
For most adults, the Mosteller formula is recommended because it's simple, accurate, and widely validated. For children, the Haycock formula is often preferred. The DuBois formula is the oldest and may slightly underestimate BSA in obese individuals.