Ideal Weight Calculator
Enter your height and sex to calculate your ideal body weight range using four established medical formulas.
What Is Ideal Body Weight?
Ideal body weight (IBW) is the weight at which a person of a given height is expected to be healthiest and have the lowest risk of weight-related disease. It is widely used in clinical settings to guide drug dosing, ventilator settings, and nutritional prescriptions — not as a cosmetic target.
There is no single universally accepted formula. This calculator shows results from four of the most widely cited equations: Devine (1974), Robinson (1983), Miller (1983), and Hamwi (1964). Each was derived from population studies and produces slightly different results. The range across all four formulas represents a reasonable target zone.
Ideal body weight is a starting point, not a verdict. Factors like body composition, age, bone density, and ethnicity mean that the healthiest weight for you personally may fall outside the calculated range. Consider ideal weight alongside BMI, body fat percentage, and advice from a healthcare professional.
The Four Formulas Explained
All four formulas use height above 5 feet (152.4 cm) as the key variable. Heights below 5 feet use a modified base value.
| Formula | Male base (kg) | Female base (kg) | Per inch over 5 ft |
|---|---|---|---|
| Devine (1974) | 50.0 | 45.5 | +2.3 kg (both) |
| Robinson (1983) | 52.0 | 49.0 | +1.9 kg / +1.7 kg |
| Miller (1983) | 56.2 | 53.1 | +1.41 kg / +1.36 kg |
| Hamwi (1964) | 48.0 | 45.5 | +2.7 kg / +2.2 kg |
Worked Examples
Example 1: Male, 178 cm (5'10"). That is 10 inches over 5 feet. Devine: 50 + (10 × 2.3) = 73.0 kg. Robinson: 52 + (10 × 1.9) = 71.0 kg. Miller: 56.2 + (10 × 1.41) = 70.3 kg. Hamwi: 48 + (10 × 2.7) = 75.0 kg. Range: 70–75 kg (154–165 lbs).
Example 2: Female, 163 cm (5'4"). That is 4 inches over 5 feet. Devine: 45.5 + (4 × 2.3) = 54.7 kg. Robinson: 49 + (4 × 1.7) = 55.8 kg. Miller: 53.1 + (4 × 1.36) = 58.5 kg. Hamwi: 45.5 + (4 × 2.2) = 54.3 kg. Range: 54–59 kg (119–130 lbs).
Example 3: Male, 190 cm (6'3"). That is 15 inches over 5 feet. Devine: 50 + (15 × 2.3) = 84.5 kg. Robinson: 52 + (15 × 1.9) = 80.5 kg. Miller: 56.2 + (15 × 1.41) = 77.4 kg. Hamwi: 48 + (15 × 2.7) = 88.5 kg. Range: 77–89 kg (170–196 lbs).
Frequently Asked Questions
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These formulas were developed decades ago from relatively small population samples. They give a reasonable ballpark but are not precise predictors of health. They are most useful in clinical settings (e.g. calculating medication doses) rather than as personal weight-loss targets.
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Being outside the calculated range does not mean you are unhealthy. Athletes with high muscle mass will often exceed ideal weight estimates. People with a smaller frame may be healthy below the range. Focus on overall health markers — blood pressure, blood glucose, cholesterol, fitness level — rather than a single number.
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No single formula is definitively superior for all populations. The Devine formula is most commonly used in clinical practice for drug dosing. Robinson and Miller were developed to improve on Devine and tend to give slightly lower estimates. Looking at the range across all four gives a more robust picture than relying on one formula alone.
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These formulas do not adjust for age. Some research suggests that slightly higher BMI (and therefore body weight) may be acceptable — and even protective — in older adults. If you are over 65, discuss weight targets with your doctor rather than relying solely on these calculations.
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Yes, though they overlap. A healthy BMI (18.5–24.9) gives a weight range; ideal weight formulas give a single point estimate. The ideal weight calculated by these formulas typically corresponds to a BMI of around 21–23, which sits in the middle of the healthy BMI range.
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Ideal weight is a theoretical health-based target. Your personal goal weight may differ based on your athletic goals, body composition, and how you feel. Use ideal weight as a reference point, not a hard target — especially if you have specific fitness or performance goals.