Body Metrics

BSA (Mosteller) Calculator

Body surface area from height and weight; the divisor for the cardiac and stroke volume indices.

Reviewed by Alex G, BSN, RN, CEN, CCRN, CMC, NREMT-P · From the Reference tab of the app

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Formula

sqrt((Height * Weight) / 3600)

How it is used

• Body Surface Area (BSA) is used to index hemodynamic parameters (e.g., converting Cardiac Output to Cardiac Index).
• It is also utilized in medical oncology for chemotherapy dosing and in burn management for fluid resuscitation.

Same formula as the app. Open it in the web app.

Related one-pagers

• Swan-Ganz (PA Catheter): Waveforms, Wedge and Normal ValuesCardiac index · 2.5–4.0 L/min/m² · CO ÷ BSA
• Hemodynamic NormalsCO = HR × SV ÷ 1000 (L/min); CI = CO ÷ BSA
• IABP Management152–162 cm (5 ft 0 to 5 ft 4) · 34 cc Linear or Sensation; 40 cc Mega or Sensation Plus · 30 cc (BSA under 1.8 m²)
• Blood Products and TransfusionRoom-temperature storage makes platelets the component most likely to carry bacteria, so units are tested or pathogen reduced; transfused platelets survive 3–4 days. For a poor rise, check a count 10–60 minutes after the dose: corrected count increment (CCI) = (post − pre count) × BSA (m²) ÷ platelets given (× 10¹¹). A 1-hour CCI below about 5,000–7,500 suggests HLA or platelet antibodies (give HLA-matched or crossmatched platelets); a good 1-hour but poor 24-hour count suggests consumption by fever, sepsis, DIC, splenomegaly or bleeding (Circular 2024).

Related calculators

• Adjusted Body Weight
• BMI

For education and exam preparation only. Follow your institution’s protocols. For education and exam preparation only. Verify results independently and follow your institution’s protocols. Not a substitute for clinical judgment.