Ideal Weight Calculator
About These Formulas
All formulas are based on height and assume a medium frame. Results are estimates and may not apply to athletes, elderly, or those with unusual body compositions.
Related Calculators
Understanding Ideal Body Weight
What is Ideal Body Weight?
Ideal Body Weight (IBW) formulas were originally developed for medical purposes—calculating drug dosages, tidal volumes for ventilation, and nutrition needs. While they provide a useful reference point, they have limitations as health indicators.
The Four Formulas
Robinson Formula (1983) - Recommended
Men: 52 kg + 1.9 kg × (inches over 5 feet)
Women: 49 kg + 1.7 kg × (inches over 5 feet)
Most commonly used and considered most accurate for general population.
Miller Formula (1983)
Men: 56.2 kg + 1.41 kg × (inches over 5 feet)
Women: 53.1 kg + 1.36 kg × (inches over 5 feet)
Tends to give slightly higher estimates, especially for taller people.
Devine Formula (1974)
Men: 50 kg + 2.3 kg × (inches over 5 feet)
Women: 45.5 kg + 2.3 kg × (inches over 5 feet)
Originally developed for drug dosage calculations. May underestimate for women.
Hamwi Formula (1964)
Men: 48 kg + 2.7 kg × (inches over 5 feet)
Women: 45.5 kg + 2.2 kg × (inches over 5 feet)
Oldest formula. May give higher estimates for taller individuals.
Limitations of IBW Formulas
What They Don't Consider
- • Body composition (muscle vs fat)
- • Age
- • Bone density
- • Ethnicity
- • Fitness level
- • Frame size
Better Health Indicators
- • Body fat percentage
- • Waist circumference
- • Waist-to-hip ratio
- • Blood pressure
- • Blood sugar levels
- • Cholesterol levels
BMI vs Ideal Weight
The healthy weight range shown uses BMI (Body Mass Index) of 18.5 to 24.9, which is considered the healthy range by most health organizations. This range accounts for natural variation in body types better than single-point IBW estimates.
| Height | Healthy Range (BMI 18.5-24.9) | Robinson IBW (Men) | Robinson IBW (Women) |
|---|---|---|---|
| 5'0" | 95-128 lbs | 115 lbs | 108 lbs |
| 5'6" | 115-154 lbs | 140 lbs | 130 lbs |
| 6'0" | 136-184 lbs | 165 lbs | 153 lbs |
| 6'6" | 160-215 lbs | 190 lbs | 175 lbs |
Important Considerations
These formulas provide general guidelines only. A muscular athlete may weigh significantly more than their "ideal weight" while being perfectly healthy. Conversely, someone at their "ideal weight" could still have health issues if they have excess body fat. Focus on overall health indicators rather than a single number. Consult with healthcare professionals for personalized guidance.
Frequently Asked Questions
Which ideal weight formula is most accurate?
The Robinson formula (1983) is generally considered most accurate for the general population. However, all IBW formulas have limitations as they don't account for body composition, frame size, or muscle mass. Use the healthy BMI range (18.5-24.9) for a more practical target weight range.
Why do different formulas give different results?
Each formula was developed for different purposes and populations. Devine (1974) was created for drug dosing calculations, while Robinson (1983) and Miller (1983) were refinements for clinical use. The differences reflect various assumptions about ideal body proportions and frame sizes.
Is my ideal weight the same as my healthy weight?
Not necessarily. Ideal weight formulas provide a single target number, while healthy weight is actually a range. A person can be healthy at various weights depending on their muscle mass, body composition, and other health markers. The BMI-based healthy range (18.5-24.9) accounts for this natural variation.
Can I be healthy at a weight different from my 'ideal' weight?
Absolutely. A muscular athlete may weigh significantly more than their calculated ideal weight while being perfectly healthy. Conversely, someone at their ideal weight could have health issues if they have high body fat. Focus on overall health indicators like body fat percentage, blood pressure, and blood sugar rather than just scale weight.