Ideal Weight Calculator
Calculate your ideal body weight range using the Hamwi, Devine, Robinson, and Miller formulas based on height and sex.
Ideal weight formulas.
Multiple medical formulas exist. The average of all four is a good indicator.
What is an Ideal Body Weight?
The concept of "Ideal Body Weight" (IBW) was originally introduced in medical science to estimate dosages for specific medications, but it has since evolved into a popular benchmark for fitness and general health. IBW represents a statistically healthy weight range associated with the lowest incidence of chronic diseases, cardiovascular events, and mortality in large-scale population studies. Rather than representing a singular "perfect" weight, it offers a reference range based on height, sex, and skeletal build.
The Four Main Formulas Compared
This calculator evaluates your ideal weight using four established medical equations: Devine, Robinson, Miller, and Hamwi. Each formula begins with a baseline weight representing a height of 5 feet (60 inches) and adds a specific weight coefficient per additional inch. While the Devine formula is the clinical standard for drug clearance estimation, the Hamwi formula is frequently used by registered dietitians. The calculator displays all four results, allowing you to see the variance and find a balanced range that fits your physiology.
Limitations of Ideal Weight Metrics
While these formulas provide useful statistical baselines, they do not account for muscle mass, bone density, or overall body composition. A highly active athlete with high muscle density may weigh significantly more than their calculated "ideal" weight while maintaining excellent health and low body fat. Therefore, IBW should be used alongside other indicators like body fat percentage, waist-to-hip ratio, and energy levels, rather than as a rigid weight-loss target.
Frequently Asked Questions
The calculator uses four widely accepted formulas: Devine (the clinical standard used for drug dosing), Robinson, Miller, and Hamwi. Each was developed for different populations and purposes. Presenting all four gives you a range rather than a single number, which is more realistic than any one formula alone.
Each formula was derived from different patient populations in different eras. For example, the Devine formula was originally created to calculate medication dosages for men. The Miller formula tends to produce lower values, while Hamwi gives slightly higher ones. The average of all four provides a balanced estimate.
Not exactly. Ideal body weight formulas give a single target number based only on height and sex. A healthy weight range accounts for BMI, body composition, age, and fitness level. For most people, the ideal weight figure falls within the normal BMI range (18.5–24.9), but athletes may weigh more due to higher muscle mass.
These adult formulas are designed for people aged 18 and over. For children and teenagers, weight-for-height is assessed using age- and sex-specific percentile growth charts from the CDC or WHO, not these fixed formulas. Consult a pediatrician for growth assessment in minors.
The results from this calculator show you a target range based on four different estimation methods. A more practical approach is to aim for a BMI between 18.5 and 24.9, which for a 5'8" (173 cm) person is roughly 57–81 kg (125–179 lbs). Your optimal personal weight also depends on muscle mass, bone density, and body composition.