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Ideal Weight Calculator

Find your ideal body weight based on your height — using four established medical formulas.

Units
Sex

Your Results

Your Ideal Weight
Average of 4 medical formulas
Devine (1974)
kg
Robinson (1983)
kg
Miller (1983)
kg
Hamwi (1964)
kg
Healthy BMI Range
BMI 18.5–24.9

These formulas were developed for adults. Results may not apply to athletes or individuals with high muscle mass.

What Is Ideal Body Weight?

Ideal body weight (IBW) is a clinical estimate of how much a person should weigh based on their height and sex. It is not a single "perfect" number — rather, it provides a reference range used in medicine for drug dosing, nutritional assessments, and health screenings.

Clinical use: Ideal body weight formulas were originally developed for drug dosing calculations — particularly for medications like antibiotics and anesthetics where dose depends on lean body mass, not total weight.

Different formulas exist because body composition varies across populations. Each formula was developed from different datasets and populations, which is why they produce slightly different results. Looking at the range across all four formulas gives a more realistic picture than relying on any single one.

The Four Formulas Explained

All four formulas use height in inches (h) and assume a baseline height of 5 feet (60 inches). For every inch above 60, a sex-specific increment is added to a base weight.

Why four formulas? Each was developed from different population datasets. The Devine formula (1974) is the most widely used in clinical practice, while Miller (1983) tends to give higher values — reflecting a more generous view of healthy weight based on insurance data.
FormulaYearMale (kg)Female (kg)
Devine197450 + 2.3 × (h − 60)45.5 + 2.3 × (h − 60)
Robinson198352 + 1.9 × (h − 60)49 + 1.7 × (h − 60)
Miller198356.2 + 1.41 × (h − 60)53.1 + 1.36 × (h − 60)
Hamwi196448 + 2.7 × (h − 60)45.5 + 2.2 × (h − 60)

Ideal Weight vs. Healthy Weight

Formula-based ideal weight is derived from height-weight relationships observed in specific populations. It gives a single point estimate and was originally designed for clinical use — particularly for calculating medication dosages and ventilator settings.

BMI-based healthy weight defines a range (BMI 18.5–24.9) that is associated with lower risk of chronic diseases in the general population. This range is broader and accounts for natural variation in body composition.

Neither metric is perfect. The ideal approach is to consider both: use the formula-based estimates as a reference point, and the BMI healthy range as the acceptable band. If your weight falls within the BMI healthy range and you feel energetic and healthy, you're likely in a good place.

Limitations

  • Muscle mass: Athletes and people with high muscle mass may have an "ideal weight" that is significantly higher than what these formulas suggest. Muscle is denser than fat, so muscular individuals weigh more at any given height.
  • Frame size: These formulas do not account for skeletal frame size. A person with a large frame will naturally weigh more than someone with a small frame at the same height.
  • Ethnicity: The original formulas were developed from predominantly Western populations. Body composition norms can differ significantly across ethnic groups.
  • Body composition: None of these formulas measure body fat percentage. Two people at the same weight can have very different amounts of fat and muscle.
  • Age: Body composition changes with age — lean mass decreases and fat mass increases. These formulas do not adjust for age-related changes.
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