How it works
The Devine formula estimates a reference body weight from height and sex using a simple linear relationship. It was published in 1974 to help clinicians estimate drug dosing weight, and has since become a widely cited shorthand for "ideal" body weight — even though it was never designed as a personal health target.
Men: IBW (kg) = 50 + 2.3 × (height in inches − 60)
Women: IBW (kg) = 45.5 + 2.3 × (height in inches − 60)
The formula is defined in inches — when your locale is set to metric, this calculator converts centimetre entries to inches internally before applying it, so the result is the same regardless of which units you typed in. The result is shown in kilograms as the primary value, with the pound equivalent always shown alongside, since ideal body weight is commonly discussed in both units.
Worked example
A man, height 70 in (5'10", 177.8 cm).
- height − 60 = 70 − 60 = 10 in.
- 2.3 × 10 = 23.
- IBW = 50 + 23 = 73 kg.
An ideal body weight of 73 kg, which is about 160.9 lb.
Common questions
What is the Devine formula?
It's a formula from 1974, originally created to estimate drug dosing weight, that's since become a common reference point for 'ideal' body weight based on height and sex. It doesn't account for frame size, muscle mass, or body composition.
Why do men and women have different formulas?
The two versions reflect average differences in body composition and frame between sexes at the same height — the constant is lower for women (45.5 vs 50) with the same per-inch adjustment above 5 feet.
Should I aim for this exact number?
Not as a strict target — it's a population-average estimate, not a personalized healthy weight range. Athletes with more muscle mass, for example, will reasonably weigh more than their Devine IBW while still being at a healthy weight.