What Is Your Ideal Weight? A Complete Guide to Healthy Body Weight
The question "how much should I weigh?" is one of the most commonly asked health questions worldwide. The answer, however, is not a single number — it is a range that depends on your height, gender, body frame, muscle mass, and overall body composition. Ideal weight formulas provide useful reference points, but they should be understood as guidelines within a broader context of health metrics rather than absolute targets to chase at any cost.
The Five Major Ideal Weight Formulas
Medical professionals and researchers have developed several formulas over the decades to estimate ideal body weight (IBW). Each was created for specific purposes and populations, and they produce slightly different results. Using multiple formulas gives you a realistic range rather than a misleadingly precise single number.
Men: IBW = 50 + 2.3 × (height in inches − 60)
Women: IBW = 45.5 + 2.3 × (height in inches − 60)
ROBINSON FORMULA (1983):
Men: IBW = 52 + 1.9 × (height in inches − 60)
Women: IBW = 49 + 1.7 × (height in inches − 60)
MILLER FORMULA (1983):
Men: IBW = 56.2 + 1.41 × (height in inches − 60)
Women: IBW = 53.1 + 1.36 × (height in inches − 60)
HAMWI FORMULA (1964):
Men: IBW = 48 + 2.7 × (height in inches − 60)
Women: IBW = 45.5 + 2.2 × (height in inches − 60)
BMI-BASED RANGE: Weight where BMI = 18.5 to 24.9
Why Different Formulas Give Different Results
Each formula was developed using different study populations and methodologies. The Devine formula, created in 1974, was originally designed for calculating medication dosages rather than setting weight goals — yet it became the de facto standard in clinical practice. The Robinson and Miller formulas were created as refinements of Devine, using updated data from larger and more diverse populations. The Hamwi formula predates all of them (1964) and tends to give slightly higher results for taller individuals. The spread between formulas typically ranges from 3–8 kg, which is actually a useful indication of the inherent uncertainty in defining "ideal" weight.
Body Frame Size and Its Impact
One limitation shared by all standard formulas is that they do not account for body frame size. A person with a naturally large skeletal frame will weigh more than a small-framed person of the same height, even at identical body fat percentages. The traditional method for estimating frame size uses wrist circumference measured at the narrowest point. For men, a wrist smaller than 16.5 cm (6.5 inches) indicates a small frame, 16.5–19 cm (6.5–7.5 inches) is medium, and above 19 cm is large. For women, the thresholds are approximately 15.2 cm and 16 cm. Small-framed individuals should aim for the lower end of the ideal weight range, while large-framed individuals can be healthy at the upper end — a difference of roughly 10% in either direction.
Beyond Numbers: What Really Defines a Healthy Weight
A truly healthy weight is better defined by health outcomes than by any formula. The weight at which your blood pressure, blood sugar, cholesterol, energy levels, and physical function are optimal is your personal ideal weight — and it may not match any formula's prediction. Modern health research increasingly emphasizes that fitness is more important than fatness: a slightly overweight person who exercises regularly has better health outcomes than a normal-weight person who is sedentary. The most important number on your body is not your weight but your waist circumference, your resting heart rate, and your body fat percentage.