Body Surface Area (BSA) is a calculated estimate of the surface area of a person's body, often used in medicine to guide drug dosing, assess organ function, and normalize physiological metrics. But what does a âhealthyâ BSA actually mean?
Average BSA Values by Demographics
While BSA varies significantly depending on height, weight, and sex, typical reference ranges have been established through population studies. Below are approximate average BSA values:
- Adult Males: 1.9 â 2.2 m²
- Adult Females: 1.6 â 1.9 m²
- Children (10â14 years): 1.2 â 1.7 m²
- Infants (1 year): 0.4 â 0.5 m²
- Newborns: 0.2 â 0.3 m²
These values represent statistical norms, not strict boundaries. Individual variation is expected and not necessarily indicative of poor health.
How BSA is Calculated
BSA is computed using height and weight inputs through empirical formulas. The most commonly used include:
- DuBois and DuBois
- Mosteller
- Haycock
- Gehan and George
Each formula has slightly different outputs, but they all correlate closely. You can try our BSA calculator to see how your values compare.
Why a BSA Range Matters
Understanding your BSA is important in clinical medicine. It is used to:
- Dose Chemotherapy Accurately: Most oncology medications are dosed per square meter (mg/m²).
- Adjust Kidney and Liver Function Results: Metrics like GFR are normalized to BSA.
- Set Baseline Values: For comparing vital signs, metabolic rate, and cardiac output.
Should I Worry if My BSA is Low or High?
A BSA value outside the âaverageâ range is not necessarily unhealthy. A tall, athletic person may have a BSA over 2.3 m² and be perfectly healthy. However, extreme values, particularly in underweight or overweight individuals, may indicate a need for clinical attentionâespecially if related to disease treatment or medication dosing.
Check Your BSA Now
Understanding your BSA can help you interpret lab values, prepare for treatments, or assess physical development.
Use our BSA calculator for accurate, formula-based results in seconds.