Ideal Weight Calculator
Calculate your ideal weight range using multiple scientifically-validated formulas. Compare results from Robinson, Miller, Devine, and Hamwi methods.
Your Information
Small frame: -10% adjustment • Medium: no adjustment • Large: +10% adjustment
Note: These formulas are designed for adults and work best for heights above 5 feet (152 cm). For heights below 5 feet, the base formula values are used.
VitalMetrics - Ideal Weight Calculator
11/2/2025
Your Ideal Weight Range
Formula Breakdown
BMI-Based Healthy Range
Weight range for BMI 18.5-24.9 (healthy weight range)
Formula Comparison
How Ideal Weight is Calculated
This calculator uses four scientifically-validated formulas to estimate ideal body weight. Each formula was developed through research on large populations and has been used clinically for decades.
Robinson Formula (1983)
Men: 52 kg + 1.9 kg per inch over 5 feet
Women: 49 kg + 1.7 kg per inch over 5 feet
An updated version of the Devine formula, the Robinson formula adjusted the coefficients based on more recent population data. It's widely used in nutrition and fitness contexts.
Miller Formula (1983)
Men: 56.2 kg + 1.41 kg per inch over 5 feet
Women: 53.1 kg + 1.36 kg per inch over 5 feet
Developed by Dr. Miller as an alternative to Robinson's formula, it uses slightly different coefficients and tends to recommend higher base weights, especially for taller individuals.
Devine Formula (1974)
Men: 50 kg + 2.3 kg per inch over 5 feet
Women: 45.5 kg + 2.3 kg per inch over 5 feet
The original and most widely known formula, developed by Dr. B.J. Devine for calculating drug dosages. It's still commonly used in medical settings and has been validated in numerous studies.
Hamwi Formula (1964)
Men: 48 kg + 2.7 kg per inch over 5 feet
Women: 45.5 kg + 2.2 kg per inch over 5 feet
The oldest formula still in use, developed by Dr. G.J. Hamwi. It's particularly popular in nutrition and dietetics for quick estimations of caloric needs based on ideal body weight.
BMI-Based Healthy Range
This range is calculated using the established healthy BMI range of 18.5-24.9. The formula calculates what your weight should be at these BMI values for your specific height: weight = BMI × (height in meters)². This provides a scientifically-backed weight range associated with the lowest health risks.
Understanding Your Results
Why Different Formulas Give Different Results
Each formula was developed at different times using different populations and methodologies. The differences you see reflect the natural variation in what researchers considered "ideal" based on health outcomes in their studies.
- •Different time periods: Body composition norms have shifted over decades
- •Different populations studied: Each researcher used different demographic groups
- •Different purposes: Some were for drug dosing, others for nutrition planning
What the Average Means
The average of all four formulas provides a reasonable target weight, but the range is more important than any single number. A healthy weight for you falls somewhere within this range, depending on your body composition, muscle mass, and frame size.
These Are Guidelines, Not Strict Targets
Your ideal weight is influenced by many factors these formulas can't account for:
- •Muscle Mass: Athletes and muscular individuals may be healthy at higher weights
- •Frame Size: Larger frames naturally carry more weight healthily
- •Age: Ideal weight may shift slightly as you age
- •Ethnicity: Different ethnic groups have different body composition norms
- •Activity Level: Very active people may be healthier at different weights
Understanding Frame Size
Frame size refers to your skeletal structure and bone thickness. People with larger frames naturally weigh more at the same height than those with smaller frames, even with similar body composition.
How to Determine Your Frame Size
Wrist Circumference Method:
- 1.Wrap your thumb and middle finger around your opposite wrist at its narrowest point (just below the wrist bone).
- 2.Small Frame: Your fingers overlap significantly
- 3.Medium Frame: Your fingers just touch or barely overlap
- 4.Large Frame: Your fingers don't touch
Frame Size Adjustments
Our calculator adjusts the ideal weight range based on your frame size:
- •Small Frame: Subtract 10% from the standard ideal weight range
- •Medium Frame: No adjustment (use standard formulas)
- •Large Frame: Add 10% to the standard ideal weight range
Why Frame Size Matters
Bone density and skeletal structure contribute to your overall weight. A person with a larger frame has heavier bones and typically more muscle mass to support that frame. This means they can be perfectly healthy at a higher weight than someone of the same height with a smaller frame.
Why Ideal Weight Varies Between Individuals
While these formulas provide useful guidelines, "ideal weight" is highly individual. Here's why:
Body Composition Matters More Than Weight
Two people at the same height and weight can look completely different and have different health profiles. A person with high muscle mass and low body fat will weigh the same as someone with low muscle mass and high body fat, but their health outcomes will be vastly different.
Athletes and Active Individuals
Highly active people and athletes often weigh more than these formulas suggest because muscle tissue is denser than fat. A muscular person may exceed their "ideal weight" while being in excellent health with low body fat percentage.
Frame Size and Bone Structure
People with larger skeletal frames naturally weigh more than those with smaller frames at the same height. These formulas use population averages and can't account for individual skeletal differences.
Age Considerations
As we age, body composition changes. Some research suggests that being slightly heavier in older age may actually be protective. These formulas were primarily developed for younger adults.
A More Complete Picture
For a comprehensive health assessment, use ideal weight alongside other measurements:
- •Body Fat Percentage: More indicative of health than weight alone
- •Waist Circumference: Indicator of visceral fat and health risks
- •BMI: Quick screening tool for weight category
- •Overall Health Markers: Blood pressure, cholesterol, blood sugar, etc.
Important Limitations
While these formulas are scientifically validated and widely used, it's important to understand their limitations:
- •Based on Population Averages: These formulas were developed using population studies. Individual variation is normal and expected. The formulas can't account for your unique body composition, genetics, or health history.
- •Don't Account for Muscle Mass: A bodybuilder and a sedentary person of the same height will get the same ideal weight recommendation, despite having completely different body compositions and health profiles.
- •One Number Isn't Right for Everyone: Health exists across a range of weights. Being slightly above or below these estimates doesn't automatically mean you're unhealthy, especially if other health markers are good.
- •Limited Height Range: These formulas work best for typical adult heights (5 feet and above). They may be less accurate for very short or very tall individuals.
- •Not for Children or Teens: These formulas are designed for adults only. Children and teenagers have different growth patterns and should use pediatric growth charts.
- •Binary Sex Classification: These formulas use traditional male/female categories and don't account for intersex individuals or those undergoing hormone therapy, who may need personalized guidance.
- •Don't Consider Health History: People with certain medical conditions, those recovering from illness, pregnant or breastfeeding individuals, and others may need different weight targets.
What Matters Most
Rather than fixating on achieving a specific number on the scale, focus on:
- •How you feel physically and mentally
- •Your energy levels and ability to do daily activities
- •Your overall health markers (blood pressure, cholesterol, etc.)
- •Maintaining healthy habits (balanced diet, regular exercise, adequate sleep)
- •A sustainable, positive relationship with food and your body
Medical Disclaimer
This Ideal Weight Calculator is for informational and educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. The formulas provide population-based estimates that may not be appropriate for your individual circumstances. Always consult with a qualified healthcare provider, registered dietitian, or certified fitness professional before making any decisions about your health or starting any weight management program. Your healthcare provider can assess your individual health status, body composition, medical history, and personal goals to provide personalized recommendations. If you have any existing health conditions, are pregnant or breastfeeding, or are taking medications, professional guidance is especially important.