Ideal Weight Calculator
Calculate your ideal weight range using multiple proven methods including Hamwi, Devine, Robinson, and Miller formulas.
Understanding Ideal Weight Calculations
What is Ideal Weight?
Ideal weight refers to a weight range that is statistically associated with optimal health outcomes. However, it's important to understand that "ideal" weight is an evolving concept. Modern perspectives recognize that health exists across a range of weights and body compositions, and factors beyond weight—such as physical fitness, metabolic health, and overall lifestyle—significantly impact well-being.
Common Ideal Weight Formulas
Hamwi Formula (1964)
For men: 106 lbs for first 5 feet + 6 lbs for each inch over 5 feet
For women: 100 lbs for first 5 feet + 5 lbs for each inch over 5 feet
Developed by Dr. G.J. Hamwi and widely used in clinical settings.
Devine Formula (1974)
For men: 50 kg + 2.3 kg for each inch over 5 feet
For women: 45.5 kg + 2.3 kg for each inch over 5 feet
Developed for medication dosing calculations.
Robinson Formula (1983)
For men: 52 kg + 1.9 kg for each inch over 5 feet
For women: 49 kg + 1.7 kg for each inch over 5 feet
An updated version incorporating more recent population data.
Miller Formula (1983)
For men: 56.2 kg + 1.41 kg for each inch over 5 feet
For women: 53.1 kg + 1.36 kg for each inch over 5 feet
Includes more variables and tends to suggest slightly higher weights.
BMI-Based Weight Range
Many health authorities define a healthy weight range as the weight that corresponds to a BMI between 18.5 and 24.9.
Formula:
BMI = Weight (kg) ÷ [Height (m)]²
For a healthy BMI range of 18.5-24.9:
Minimum Weight = 18.5 × [Height (m)]²
Maximum Weight = 24.9 × [Height (m)]²
Example Calculation:
For a person 170 cm tall (1.7 m):
- Minimum weight = 18.5 × (1.7)² = 18.5 × 2.89 = 53.5 kg
- Maximum weight = 24.9 × (1.7)² = 24.9 × 2.89 = 72.0 kg
- Healthy weight range = 53.5 - 72.0 kg
Note: BMI has limitations as it doesn't account for body composition, muscle mass, bone density, or fat distribution. It serves as a general population screening tool rather than an individual health assessment.
Body Frame Size
Small Frame
People with small frames typically have narrow shoulders and wrists, less bone mass, and a generally slender build. For the same height, those with small frames may naturally weigh less than average. Small-framed individuals have wrist circumferences less than 6.25" (men) or 5.5" (women).
Medium Frame
Medium frame represents average bone structure and is the most common frame size in the population. These individuals have balanced proportions and moderate bone mass relative to their height. Most ideal weight formulas are calibrated for medium-framed individuals.
Large Frame
People with large frames have broader shoulders, bigger bones, and typically more overall mass relative to their height. Large-framed individuals may weigh more than average while still maintaining a healthy body composition. Large-framed individuals have wrist circumferences more than 7.25" (men) or 6.5" (women).
Determining Your Frame Size
While there are several methods to estimate frame size, a simple approach involves measuring your wrist:
Men's Frame Size:
- Small: Wrist circumference less than 6.25 inches
- Medium: Wrist circumference between 6.25 and 7.25 inches
- Large: Wrist circumference more than 7.25 inches
Women's Frame Size:
- Small: Wrist circumference less than 5.5 inches
- Medium: Wrist circumference between 5.5 and 6.5 inches
- Large: Wrist circumference more than 6.5 inches
Limitations of Ideal Weight Calculations
- Body composition: Ideal weight formulas don't account for the ratio of muscle to fat. Athletes with high muscle mass may be healthy at weights above the calculated "ideal" range.
- Ethnic and genetic variations: Different populations may have different body compositions and health outcomes at the same weights.
- Age considerations: Older adults may maintain health at different weight ranges than younger people. Bone density and muscle mass naturally change with age.
- Historical context: Many of these formulas were developed decades ago and may not fully reflect modern understanding of health and weight.
- Individual health factors: Personal health conditions, metabolic rate, and lifestyle factors can affect what weight is truly "ideal" for an individual.
- Focus on weight alone: Weight is just one indicator of health. Blood pressure, cholesterol levels, blood sugar, fitness level, and mental health are equally important factors.
Health Beyond Weight
Body Composition vs. Weight
Body composition (the ratio of fat to lean mass) is often more relevant to health than weight alone. Two people of identical height and weight can have dramatically different body compositions and health profiles. Measures like body fat percentage provide more meaningful health information than weight alone.
Example: A 175cm tall man weighing 80kg could be either a professional athlete with 12% body fat or a sedentary individual with 30% body fat. Despite having the same height and weight, their health profiles would be vastly different.
Metabolic Health Indicators
Research increasingly supports the concept of "metabolically healthy" individuals across different weight ranges. Key health indicators include:
- Blood pressure
- Blood glucose levels
- Cholesterol and triglyceride levels
- Insulin sensitivity
- Inflammatory markers
- Cardiorespiratory fitness
- Muscle strength and mobility
Important Considerations
Ideal weight calculations should be viewed as general references rather than strict targets. Individual health goals should be set in consultation with healthcare providers, considering personal health history, body composition, fitness level, metabolic health, and overall well-being. Focus on sustainable lifestyle habits like balanced nutrition, regular physical activity, quality sleep, and stress management, rather than achieving a specific weight number. Remember that health exists at many sizes, and weight is just one of many metrics in the broader context of health.