Ideal body weight calculator
Ideal body weight by the Devine formula, with the Robinson and Miller variants.
The formulas were derived with separate male and female constants.
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This is a reference implementation of a published formula, provided for use by qualified healthcare professionals. It does not diagnose, does not account for the individual circumstances of any patient, and is not a recommendation for treatment. Confirm every result against your own institutional guidance before acting on it. Clinical judgement always takes precedence over a calculator.
About this calculation
Ideal body weight is a dosing construct rather than a health target. It is used where a drug distributes into lean tissue, and for setting tidal volume in lung-protective ventilation.
Formula
Devine — male: 50 kg + 2.3 kg per inch over 60 in. Female: 45.5 kg + 2.3 kg per inch over 60 in.
- Source
- Devine BJ, Drug Intelligence and Clinical Pharmacy (1974)
- Methodology version
- 1.0.0
- Last reviewed
- 2026-10-28
What this does not account for
- The Devine formula was devised for dosing, not to describe a healthy weight, and should not be presented to a patient as a target.
- Below 60 inches (152 cm) the formula is an extrapolation; approaches differ and some subtract 2.3 kg per inch below 60.
- For a patient substantially above ideal weight, many drugs are dosed on adjusted body weight instead.