15 / Dosing Basics
Body Weight & BSA
Ideal and adjusted body weight, BMI and body surface area
IBW (Devine) = 50 (♂) or 45.5 (♀) + 2.3 × (height in inches − 60)
Patient Information
Sex
Height
cm
Weight — actual
kg
Result
—
—
Interpretation
Enter values above.
Notes & Sources
- Which weight for which drug. Hydrophilic drugs (aminoglycosides, many β-lactams) are usually dosed on IBW or adjusted body weight; lipophilic drugs may use actual weight. Always follow the drug-specific reference rather than a general rule.
- Adjusted body weight uses a correction factor of
0.4: AdjBW = IBW + 0.4 × (actual − IBW). It is conventionally applied when actual weight exceeds IBW by more than 20–30%. - The Devine formula is an estimate derived for adults and becomes unreliable below about 152 cm (60 inches), where it can return implausibly low values.
- BSA is shown by both Mosteller and DuBois. Mosteller is the more common choice for chemotherapy dosing because it is simpler and the two agree closely in most adults.