Nutrition
Ideal body weight
Ideal body weight is a reference weight derived from height and sex, used for dosing and for ventilator tidal volumes. Adjusted body weight, shown alongside, is what several drug protocols actually ask for in obesity.
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This calculator is provided for reference and education. It does not replace clinical assessment, examination, current guidelines, local protocol, or professional judgment. Verify every result before acting on it. Nirogix accepts no liability for clinical decisions made using this tool.
The formula
- Devine: men 50 kg + 2.3 × (inches over 60); women 45.5 kg + 2.3 × (inches over 60)
- Robinson: men 52 + 1.9 per inch; women 49 + 1.7 per inch
- Miller: men 56.2 + 1.41 per inch; women 53.1 + 1.36 per inch
- Hamwi: men 48 + 2.7 per inch; women 45.5 + 2.2 per inch
- Adjusted body weight = IBW + 0.4 × (actual − IBW)
Worked example
A man of 175 cm (68.9 in), Devine → 50 + 2.3 × 8.9 = 70.5 kg
When to use it
- Setting ventilator tidal volumes
- Dosing a drug written against ideal or adjusted body weight
And when not to
- These formulas were derived in Western populations and read high for many Indian adults. Treat them as a reference point, not a target weight to tell a patient.
- Below 5 feet the formulas extrapolate poorly.
- It is not a healthy-weight goal. That conversation belongs to BMI and waist circumference.
References
- Gentamicin therapy — Devine BJ, Drug Intelligence and Clinical Pharmacy, 1974
- Determination of ideal body weight for drug dosage calculations — Robinson JD et al., American Journal of Hospital Pharmacy, 1983
Last reviewed 07/09/2026.
These calculators are free and always will be. We also build Nirogix, a hospital management system for Indian clinics and hospitals. The same calculations are planned inside the consultation record, pre-filled from the chart.