Ideal Weight Calculator
Calculate your ideal body weight using multiple medical formulas. Get personalized ranges adjusted for body frame size with Devine, Robinson, Miller, and Hamwi calculations.
Wrist test: Small (<6.5"), Medium (6.5-7.5"), Large (>7.5") for men
How to Calculate Ideal Weight
Step 1: Select Units
Choose metric (kg, cm) or imperial (lbs, ft/in) based on your preference. All formulas work with both measurement systems.
Step 2: Enter Gender
Select your biological sex. Formulas use different coefficients for males and females due to differences in average body composition and bone density.
Step 3: Input Height
Enter your height in centimeters (metric) or feet and inches (imperial). Accurate height is crucial since formulas are height-based.
Step 4: Choose Body Frame
Determine your frame size using the wrist test. Small frames: -10% adjustment, Medium: baseline, Large: +10% adjustment. This personalizes your range.
Step 5: View Results
See average ideal weight (4 formulas), frame-adjusted range, individual formula breakdowns, and BMI-based healthy range for comprehensive guidance.
Step 6: Interpret Wisely
Use results as general guidance, not strict targets. Consider muscle mass, fitness level, and overall health. Consult healthcare professionals for personalized advice.
Medical Weight Formulas Explained
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
Developed by Dr. B.J. Devine for dosing medications. Most widely used formula in clinical settings. Conservative estimates.
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
Modified Devine formula with adjusted coefficients. Often used in nutrition assessments. Tends slightly higher than Devine.
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
Alternative approach with different base weights. Used in some clinical protocols. Generally middle-range estimates.
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
Original medical formula developed for diabetic nutrition. Tends toward higher estimates. Still referenced in medical literature.
Determining Your Body Frame Size
Wrist Circumference Method
Men
- • Small Frame: <6.5 inches
- • Medium Frame: 6.5-7.5 inches
- • Large Frame: >7.5 inches
Women
- • Small Frame: <6 inches
- • Medium Frame: 6-6.5 inches
- • Large Frame: >6.5 inches
Thumb-and-Finger Test (Alternative)
- 1. Wrap thumb and middle finger around opposite wrist
- 2. Fingers overlap significantly = Small frame
- 3. Fingers just touch = Medium frame
- 4. Fingers don't touch = Large frame
Note: This is an approximation. Wrist measurement is more accurate.
Frequently Asked Questions
How is ideal body weight calculated?
Ideal body weight is calculated using medical formulas like Devine (1974), Robinson (1983), Miller (1983), and Hamwi (1964). These formulas consider height and gender to estimate a healthy weight range. Our calculator averages all four formulas and adjusts for body frame size (±10%).
What is the most accurate ideal weight formula?
The Devine formula (1974) is most widely used by healthcare professionals. However, no single formula is universally accurate. We average four established formulas (Devine, Robinson, Miller, Hamwi) to provide a more balanced estimate. BMI-based ranges (18.5-24.9) offer an alternative approach.
How do I determine my body frame size?
Wrist circumference test: For men - Small: <6.5", Medium: 6.5-7.5", Large: >7.5". For women - Small: <6", Medium: 6-6.5", Large: >6.5". Alternatively, wrap thumb and middle finger around opposite wrist. If they overlap significantly = small, just touch = medium, don't touch = large.
Why do different formulas give different results?
Each formula was developed by different researchers using different populations and methodologies. Devine (1974) is most conservative, Hamwi (1964) tends higher, while Robinson and Miller (both 1983) fall in between. Differences typically range 5-10 lbs, which is why averaging provides a better estimate.
Is ideal weight the same as healthy weight?
Not exactly. Ideal weight formulas estimate average healthy weight for height/gender, but don't account for muscle mass, bone density, or body composition. Athletes may exceed 'ideal' weight while being very healthy. BMI ranges (18.5-24.9) and body fat percentage provide additional context.
Should I weigh exactly my ideal weight?
No. Ideal weight is a range, not a specific target. Our calculator provides a 10-20% range based on frame size. Being within this range while maintaining healthy habits (nutrition, exercise, sleep) is more important than hitting an exact number. Focus on overall health, not just the scale.
Do these formulas work for bodybuilders or athletes?
Not well. These formulas assume average body composition (15-25% body fat). Bodybuilders and athletes with high muscle mass will naturally exceed 'ideal' weight calculations but be perfectly healthy. For athletic populations, body fat percentage and lean mass measurements are more appropriate.
How does age affect ideal weight?
These formulas don't adjust for age, though some research suggests slightly higher weights in older adults (65+) may be protective. Muscle loss with aging (sarcopenia) is a bigger concern than weight gain. Maintaining muscle mass through strength training is crucial at all ages.
What if my ideal weight is very different from my current weight?
Large discrepancies require gradual, sustainable changes. Aim for 0.5-2 lbs per week weight loss (1-2% per month). Rapid changes are rarely sustainable. Focus on building healthy habits (nutrition, exercise, sleep, stress management) rather than quick fixes. Consult a healthcare provider for personalized guidance.
Can I use this calculator for children or teens?
No. These formulas are designed for adults (18+). Children and adolescents have different growth patterns and should use pediatric growth charts with BMI-for-age percentiles. Consult a pediatrician for healthy weight assessment in children and teens.