Ideal Weight Calculator
The ideal weight calculator computes your healthy weight range using four established medical formulas: Devine, Robinson, Miller, and Hamwi. Enter your height and sex to see the result from each formula alongside your current weight. Metric and imperial. Free, no account needed.
♀ 45.5 + 2.3 × (inches above 5′)
♀ 49 + 1.7 × (inches above 5′)
♀ 53.1 + 1.36 × (inches above 5′)
♀ 45.4 + 2.2 × (inches above 5′)
How to use Ideal Weight Calculator
- Select your unit system: metric or imperial.
- Enter your height using the input fields.
- Select your sex.
- The calculator shows your ideal weight range from four formulas: Devine, Robinson, Miller, and Hamwi.
- Compare your current weight against each formula's target range.
Healthy weight for my height: the four formula approach
The ideal body weight formulas were originally developed for clinical use, primarily to calculate drug dosages that scale with lean body mass rather than total body weight. The Devine formula (1974) is the most widely cited and still commonly used in pharmacology. The Robinson formula (1983) and Miller formula (1983) were developed as refinements to Devine. The Hamwi formula (1964) is the oldest and uses a rule-of-thumb approach based on a base weight at 5 feet with an increment per additional inch. The healthy weight for my height from each formula is slightly different, which is why displaying all four simultaneously is more informative than relying on any single formula.
The results from the four formulas define a range rather than a single target weight. Your healthy weight is best understood as falling within this range rather than hitting a precise number. A person standing 170 cm tall might see results ranging from 64 kg to 69 kg across the four formulas, and any weight within or near that spread is consistent with a healthy body weight for their frame. Use the ideal weight range alongside your BMI result and body fat percentage for a more complete picture of where your weight sits relative to health norms.
What should I weigh: context for your results
Target weight by height is a useful reference point but should not be treated as a rigid target. Individual variation in bone density, muscle mass, and body frame means that two people of the same height and sex can be equally healthy at different weights. Athletes and individuals with high muscle mass will typically sit above the ideal weight calculator range without any health concern. Older adults may also have different body composition at the same weight compared to younger individuals.
Ideal weight for women by height results typically come out lower than for men at the same height, because the four formulas incorporate sex-specific constants. Women naturally carry a higher percentage of body fat and a lower proportion of lean mass than men at any given height, and the formulas reflect this. Use the what should I weigh result as a health context reference point combined with your BMI and body fat percentage, rather than as a performance target.
Frequently asked questions
Each formula uses height (converted to inches above 5 feet) and sex to calculate ideal body weight. Devine: 50 kg + 2.3 × (inches above 5 feet) for men; 45.5 kg + 2.3 × (inches above 5 feet) for women. Robinson: 52 kg + 1.9 × (inches above 5 feet) for men; 49 kg + 1.7 × (inches above 5 feet) for women. Miller: 56.2 kg + 1.41 × (inches above 5 feet) for men; 53.1 kg + 1.36 × (inches above 5 feet) for women. Hamwi: 48 kg + 2.7 × (inches above 5 feet) for men; 45.4 kg + 2.2 × (inches above 5 feet) for women.
Each formula was developed independently in a different decade using different clinical datasets and methodologies. The differences between formulas reflect genuine scientific uncertainty about what constitutes an ideal weight for a given height, the formulas were primarily designed for drug dosing applications, not as consumer health targets. The spread between the highest and lowest formula result for a given height is typically 3 to 7 kg, illustrating that ideal weight is a range rather than a single fixed number.
Yes. All four formulas produce different results for men and women at the same height. Men's ideal weight is typically 4 to 6 kg higher than women's at the same height across all four formulas. This reflects physiological differences in bone density and muscle mass between sexes. The formulas do not account for individual variation in frame size, a large-framed individual will typically carry more weight than the formula suggests without any health risk.
No. The ideal body weight formulas were developed for clinical drug dosing, not as universal fitness targets. They do not account for body composition, a person with high muscle mass and low body fat may exceed ideal weight ranges significantly without any health risk. The formulas are most useful as a general reference for people within the normal range of body composition. For muscular individuals, athletes, or people with unusually high or low bone density, the body fat percentage calculator provides a more relevant measure than ideal weight formulas.