Ideal Body Weight Calculator

This calculates a person's ideal body weight from height and sex using the Devine formula — the same calculation used inside the ARDSnet tidal volume tool, offered here on its own.

Calculate Ideal Body Weight

cm
Standing height (Devine formula).
Enter a value between 120 and 220.
Ideal Body Weight
65.9
kg
Ideal body weight
In pounds
145.4 lb
Height
66.9 in

How It's Calculated

Devine formula (height in inches)
Male: 50 + 2.3 × (height − 60) · Female: 45.5 + 2.3 × (height − 60)

Frequently Asked Questions

Why use ideal body weight instead of actual body weight for medical calculations?

Many physiologic calculations, like lung-protective ventilation, scale with lean body size rather than total body mass. Using actual weight in an obese patient can lead to dangerously oversized settings.

What is the Devine formula?

Male: 50 kg + 2.3 kg per inch over 5 feet. Female: 45.5 kg + 2.3 kg per inch over 5 feet. It estimates ideal body weight from height and sex.

Where is ideal body weight used?

Lung-protective tidal volume (ARDSnet), some drug dosing, and other calculations that depend on lean size rather than fat mass.

Does it work for very short patients?

The Devine formula becomes unreliable well below 5 feet; other height-based formulas or clinical judgment are used at the extremes.

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