Ideal Body Weight (IBW) Calculator

Ideal Body Weight (IBW) Calculator

Ideal body weight (IBW) is an estimate of a healthy weight based on height and sex. It is used for medication dosing, nutritional assessment, and clinical decision-making, especially in critical care and anesthesia.

Common IBW Formulas

• Devine (1974):
  $$\text{Male:}50+2.3\times \left(\text{height [in] - 60}\right)$$
• Robinson (1983):
  $$\text{Male:}52+1.9\times \left(\text{height [in] - 60}\right)$$
• Miller (1983):
  $$\text{Male:}56.2+1.41\times \left(\text{height [in] - 60}\right)$$
• Hamwi (1964):
  $$\text{Male:}48+2.7\times \left(\text{height [in] - 60}\right)$$

Interpretation

• IBW is an estimate, not an absolute value.
• Use for medication dosing (e.g., aminoglycosides, anesthetics), nutritional assessment, and clinical decision-making.
• Consider actual body weight, BMI, and clinical context.

Clinical Applications

• Medication dosing: Especially for drugs with narrow therapeutic index or toxicity risk.
• Nutritional assessment: Guide caloric and protein requirements.
• Critical care/anesthesia: Used for ventilator settings, fluid management, and drug dosing.

Limitations

• Not validated for children, pregnant women, or those with extreme body composition.
• May not reflect optimal weight for all individuals.
• Should not be used as the sole criterion for clinical decisions.

Important Considerations

• Always interpret IBW in the context of the full clinical picture.
• Document IBW and calculation method in the medical record.
• Consult clinical guidelines for specific drug dosing recommendations.