Ideal Weight Calculator
Calculate your ideal body weight using five proven medical formulas. Compare results from Devine, Robinson, Miller, Hamwi, and BMI-based methods to find your healthy weight range.
Wrist measurement can help estimate frame size
🎯 Healthy Weight Range (BMI 18.5–24.9)
Formula Comparison
| Formula | Ideal Weight | Notes |
|---|---|---|
| Devine (1974) | -- | Most commonly used in clinical settings |
| Robinson (1983) | -- | Modification of Devine formula |
| Miller (1983) | -- | Tends to give slightly higher values |
| Hamwi (1964) | -- | Oldest formula, still widely used |
| BMI-Based (22) | -- | Uses target BMI of 22 |
Understanding Ideal Weight Formulas
Several formulas have been developed to estimate ideal body weight based on height. Each has its origins, strengths, and limitations. None is perfect for everyone—use them as guidance, not gospel.
Devine Formula (1974)
Originally developed for drug dosing calculations. The most widely used formula in clinical medicine, though based on limited data.
Robinson Formula (1983)
A modification of Devine's work, calculating slightly different values, especially for women.
Miller Formula (1983)
Tends to produce higher ideal weights than other formulas, which some find more realistic.
Hamwi Formula (1964)
One of the oldest methods, developed by Dr. George Hamwi. Still commonly used in nutrition contexts.
Formula Equations
Inches over 5 feet = 10 inches
Devine: 50 + 2.3 × 10 = 50 + 23 = 73 kg (161 lb)
Robinson: 52 + 1.9 × 10 = 52 + 19 = 71 kg (156 lb)
Miller: 56.2 + 1.41 × 10 = 56.2 + 14.1 = 70.3 kg (155 lb)
Hamwi: 48.0 + 2.7 × 10 = 48 + 27 = 75 kg (165 lb)
Inches over 5 feet = 6 inches
Devine: 45.5 + 2.3 × 6 = 45.5 + 13.8 = 59.3 kg (131 lb)
Robinson: 49 + 1.7 × 6 = 49 + 10.2 = 59.2 kg (130 lb)
Miller: 53.1 + 1.36 × 6 = 53.1 + 8.16 = 61.3 kg (135 lb)
Hamwi: 45.5 + 2.2 × 6 = 45.5 + 13.2 = 58.7 kg (129 lb)
Frame Size Adjustments
Frame size accounts for differences in bone structure. Traditionally:
- Small frame: Subtract 10% from calculated ideal weight
- Medium frame: Use calculated value as-is
- Large frame: Add 10% to calculated ideal weight
Frequently Asked Questions
None is universally accurate. The Devine formula is most commonly used in clinical settings, but all formulas have limitations. The BMI-based healthy range is often considered more practical since it allows for individual variation.
Each formula was developed using different study populations and methodologies. They represent different perspectives on what constitutes "ideal" weight. The variation shows there's no single correct answer.
No. They don't account for muscle mass, bone density, or body composition. Athletes and highly muscular individuals may appear "overweight" by these standards while being very healthy.
"Ideal weight" formulas were often developed for specific clinical purposes (like drug dosing). "Healthy weight" is a broader concept—the BMI range of 18.5-24.9 captures a wider range of weights that are generally associated with good health outcomes.
A common method is measuring wrist circumference. For men: small frame < 6.5", medium 6.5-7.5", large > 7.5". For women: small < 6", medium 6-6.5", large > 6.5". These are approximate guidelines.
No. These formulas are designed for adults. Children and adolescents should use age-appropriate growth charts and BMI-for-age percentiles, usually tracked by pediatricians.
These formulas were developed decades ago when average body weights were lower. They may underestimate healthy weights for modern populations, especially for muscular individuals or those from diverse ethnic backgrounds.
Use these numbers as one data point, not an absolute goal. Focus on overall health markers: blood pressure, cholesterol, blood sugar, energy levels, and how you feel—not just a number on the scale.
Instead of a formula, this method calculates what weight would give you a target BMI (typically 22, the middle of the healthy range). It's derived as: Weight = BMI × Height².
The formulas account for sex but not age. As people age, body composition changes (less muscle, more fat). Some experts suggest slightly higher weights may be appropriate for older adults.
Yes, particularly the Devine formula for medication dosing and nutritional assessments. However, doctors also consider clinical judgment, blood tests, and overall health rather than weight alone.
These formulas become less accurate at extreme heights. For people under 5 feet or over 6.5 feet, the BMI-based healthy range may be more appropriate than the formula calculations.