Ideal Body Weight

Devine ideal and adjusted body weight for dosing.

Sex

Height (cm)

Actual weight (kg)

Devine formula. Adjusted body weight (IBW + 0.4 × [actual − IBW]) is often used for weight-based dosing in obese patients. Education only — follow local protocol.

Ideal body weight

70.5

Adjusted body weight

74.3 kg

IBW + 0.4 × (actual − IBW)

Ideal and adjusted body weight

Ideal body weight (IBW) estimates a healthy weight for a given height, and adjusted body weight refines weight-based dosing in obese patients. Both help dose drugs and local anaesthetics more safely.

The Devine formula

Devine IBW = 50 kg (men) or 45.5 kg (women) + 2.3 kg per inch over 5 feet. Adjusted body weight = IBW + 0.4 × (actual − IBW).

When to use adjusted weight

For many drugs, dosing on total body weight overshoots in obese patients while IBW alone may underdose; adjusted body weight is a common compromise. Always check the specific drug's recommendation.

Education only — follow the drug's licensed dosing and local protocol.