Explore the different formulas used by medical professionals to calculate Ideal Body Weight (IBW) and what it means for your health.
"What should I weigh?" It's a common question, but there is no single perfect number that applies to everyone. Ideal Body Weight (IBW) is a range determined by your height, gender, and sometimes frame size. You can find your scientifically estimated range using our Ideal Weight Calculator.
Popular Formulas for Calculating IBW
Over the years, several formulas have been developed by scientists to estimate ideal weight. Most of them establish a base weight for a height of 5 feet, and then add a specific amount of weight for every inch above 5 feet.
1. The J.D. Robinson Formula (1983)
This is one of the most commonly used formulas today.
- Men: 52 kg + 1.9 kg per inch over 5 feet.
- Women: 49 kg + 1.7 kg per inch over 5 feet.
2. The Devine Formula (1974)
Originally intended to calculate doses of certain medications, it became widely used as an IBW indicator.
- Men: 50 kg + 2.3 kg per inch over 5 feet.
- Women: 45.5 kg + 2.3 kg per inch over 5 feet.
3. The Miller Formula (1983)
- Men: 56.2 kg + 1.41 kg per inch over 5 feet.
- Women: 53.1 kg + 1.36 kg per inch over 5 feet.
The Concept of Frame Size
Most IBW formulas don't account for body frame size (small, medium, or large). Two people of the same height can have very different bone structures and muscle mass. A person with a large frame will naturally have a higher ideal weight than a person with a small frame of the exact same height.
Because of this, it is better to think of your "ideal" weight as a range of 10-15 pounds rather than a single specific number.
IBW vs. BMI
While IBW gives you a specific target weight (or range), Body Mass Index (BMI) is a ratio of weight to height that categorizes you into brackets (underweight, normal, overweight, obese). A healthy BMI generally corresponds to a weight range that surrounds your IBW.
A Holistic Approach to Weight
Weight is just one metric of health. Your body fat percentage, cardiovascular endurance, muscle mass, and dietary habits are equally, if not more, important indicators of overall wellness. An athlete might weigh significantly more than their IBW due to heavy muscle mass but still be exceptionally healthy.
Calculate your personalized range using all major scientific formulas with our Ideal Weight Calculator.