Ideal Body Weight (IBW) Calculator
Estimate ideal body weight using the Devine formula from height and sex — common reference for ventilator settings and dosing context.
Understanding this tool
Why nurses use it
Ideal body weight (IBW) from the Devine formula supports ventilator tidal volume targets (6–8 mL/kg IBW), aminoglycoside context, and other protocol references — especially when actual weight is elevated.
When to use it
Use when a protocol specifies IBW from height and sex for adults — not as a general healthy weight goal. Not for pediatric dosing.
Calculate
How to use this calculator
- Enter height and sex.
- Use IBW only as referenced by the specific clinical protocol.
How the calculation works
Devine: males IBW = 50 kg + 2.3 kg per inch over 5 ft; females 45.5 kg + 2.3 kg per inch over 5 ft.
Formula used by this tool — verify units before applying at the bedside.
Worked example
Limitations & clinical notes
- Devine formula is one of several; institution may specify alternate IBW equation.
- Not a substitute for clinical judgment in obesity.
- Adult estimate only — not validated for pediatric dosing; very short adults may need clinical judgement.
References
Key sources: Devine BJ — Gentamicin dosing (1974).
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Disclaimer: This calculator is for educational and bedside double-check purposes only. It does not replace institutional protocols, prescriber orders, pharmacist verification, or clinical judgment. Always follow your local policies — especially for high-risk medications, infusions, pediatrics, and critical care. If the patient is acutely unwell, escalate immediately rather than relying on any calculator output.