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Endocrinology and metabolism

Ideal Body Weight (IBW)

2 inputsEndocrinology and metabolism

Devised by Devine for medication dosing.

Ideal Body Weight (IBW) calculator

Result

65.9kg

Adjusted BW (if obese) ≈ IBW + 0.4×(ABW−IBW)

Devine formula. Aminoglycosides, LMWH, ventilator tidal volume use IBW.

100 to 250 cm

Sex

How to use it

  1. 1

    Devine formula. Male: 50 + 2.3 kg per inch over 5 ft. Female: 45.5 + 2.3 per inch over 5 ft.

  2. 2

    Adjusted body weight (AdjBW) for obese patients. AdjBW = IBW + 0.4 × (ActualBW − IBW).

  3. 3

    Ventilation. Tidal volume for mechanical ventilation = 6 mL/kg × IBW.

When to use it

Mechanical ventilation
Lung-protective tidal volume based on IBW, NOT actual body weight.
Aminoglycoside dosing
Amikacin, gentamicin: mg/kg IBW (or AdjBW if obese).
LMWH dosing
Enoxaparin: cap at 144 mg/day in severe obesity; some centres use AdjBW.

A reference for clinicians and students, not medical advice. A score supports a decision; it does not make one. Check every result against the patient in front of you and your local protocol.

At a glance

Specialty
Endocrinology and metabolism
Inputs
2
Type
Formula

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