Ideal body weight (IBW) is a target weight range based on height, frame size, and sex. Multiple formulas exist (Devine, Hamwi, Robinson, Miller), each producing slightly different results.
Common IBW Formulas
The Devine formula (most widely used in medicine): Men: 50 kg + 2.3 kg per inch over 5 feet. Women: 45.5 kg + 2.3 kg per inch over 5 feet.
These formulas were originally developed for medication dosing, not as weight goals. They do not account for body composition, muscle mass, or age.
Why Ranges Matter
There is no single "ideal" weight. A healthy weight range depends on body composition, fitness level, age, and individual health markers. Two people at the same height can have very different healthy weights based on muscle mass and frame size.
Real-World Example
For a 5'8" male: Devine formula = 50 + (2.3 × 8) = 68.4 kg (151 lbs). Hamwi formula gives 154 lbs. Robinson gives 155 lbs. The range of 151-155 lbs serves as a general reference point, not a strict target.
Frequently Asked Questions
Is ideal body weight the same as healthy weight?
Not exactly. IBW formulas provide a mathematical estimate, while a healthy weight considers the full picture: body fat percentage, blood pressure, cholesterol, blood sugar, fitness level, and how you feel. Many people are healthy above or below their calculated IBW.
Which IBW formula is best?
The Devine formula is most commonly used in clinical settings. However, all IBW formulas are simplistic. For personal goals, using a BMI range of 20-25 combined with body fat percentage gives a more personalized and useful target.
Does frame size affect ideal weight?
Yes. People with larger bone structure may have a healthy weight 10-15% above standard IBW formulas. Wrist circumference and elbow breadth are common methods for estimating frame size (small, medium, or large).