What is Ideal Body Weight?
Ideal body weight (IBW) is an estimate of the optimal weight for a person based on their height and gender. It represents the weight at which individuals of a given height typically have the lowest health risks and optimal physiological function. Medical researchers have developed several formulas over the decades to calculate IBW based on population studies and health outcome data.
Key Features:
- Four Medical Formulas: Robinson, Miller, Devine, and Hamwi formulas for comprehensive estimation
- Gender-Specific Calculations: Separate formulas adjusted for biological differences between men and women
- Frame Size Adjustment: Account for skeletal structure (small, medium, large frames)
- BMI-Based Healthy Range: See your recommended weight range based on health standards
- Instant Results: Get multiple formula estimates and averages immediately
- Privacy First: All calculations done locally on your device
The Four Ideal Weight Formulas
Robinson (1983)
Most commonly used in modern medical practice. Males: 52 kg + 1.9 kg per inch over 5'. Females: 49 kg + 1.7 kg per inch over 5'.
Miller (1983)
Similar to Robinson with slightly different coefficients. Males: 56.2 kg + 1.41 kg per inch. Females: 53.1 kg + 1.36 kg per inch.
Devine (1974)
Widely used in pharmaceutical and medical settings for drug dosing. Males: 50 kg + 2.3 kg per inch. Females: 45.5 kg + 2.3 kg per inch.
Hamwi (1964)
Oldest formula, designed for quick calculations. Males: 48 kg + 2.7 kg per inch. Females: 45.5 kg + 2.2 kg per inch.
Understanding Frame Size
Frame size refers to your skeletal structure. People with larger frames naturally weigh more due to heavier bones and larger joints, even at the same body fat percentage. Frame size can adjust your ideal weight by ±10%.
Determine Your Frame Size
| Gender | Small Frame | Medium Frame | Large Frame |
|---|---|---|---|
| Men (Wrist) | < 6.5" (16.5 cm) | 6.5-7.5" (16.5-19 cm) | > 7.5" (19 cm) |
| Women (Wrist) | < 5.5" (14 cm) | 5.5-6.25" (14-16 cm) | > 6.25" (16 cm) |
Measure your wrist circumference at the narrowest point where it bends to determine your frame size.
⚕️ Medical Disclaimer
For Informational Purposes Only
This calculator provides estimates only and is not a substitute for professional medical advice, diagnosis, or treatment.
This ideal weight calculator provides estimates based on established medical formulas for educational and informational purposes only. It should not be used as the sole basis for medical decisions.
Frequently Asked Questions
What is ideal body weight (IBW)?
Ideal body weight is an estimate of the optimal weight based on height and gender. It's calculated using medical formulas developed by researchers. IBW serves as a guideline but should be adjusted based on factors like muscle mass, bone density, and overall health.
Which formula is most accurate?
The Robinson formula (1983) is most commonly used in modern medicine. However, all four formulas are valid. Our calculator averages all four to provide the most reliable estimate. Differences typically range 2-5 kg.
How does frame size affect ideal weight?
Frame size refers to your skeletal structure. Larger frames support more weight, while smaller frames support less. Our calculator adjusts the ideal weight ±10% based on frame size for a more personalized recommendation.
Is ideal weight the same as healthy weight?
Not exactly. Ideal weight formulas give a specific target based on population averages. Healthy weight is a broader range (typically BMI 18.5-25) that accounts for individual variation in body composition and muscle mass.
Can I use ideal weight for weight loss goals?
Yes, ideal weight can serve as a reasonable goal for weight loss. However, focus on healthy body composition rather than just a number on the scale. Aim for gradual weight loss (0.5-1 kg per week) combined with strength training.
Is ideal weight accurate for athletes?
No, these formulas don't account for high muscle mass. Athletes often exceed their calculated ideal weight while being very healthy. For athletes, body composition analysis (body fat percentage) is a better health indicator.
How does BMI differ from ideal weight?
BMI provides a healthy weight range based on height. Ideal weight formulas calculate a specific target weight. Both are useful: BMI for general categories, ideal weight for precision targets.
Should older adults use these formulas?
These formulas were developed for younger and middle-aged adults. For older adults (65+), slightly higher weights may be protective. Focus on maintaining muscle mass and functional fitness rather than achieving lower weights.
What if I'm significantly above or below my ideal weight?
Set intermediate goals rather than trying to reach ideal weight immediately. Aim for 5-10% weight change first. Consult a healthcare provider or registered dietitian for personalized guidance and sustainable strategies.
Does ideal weight account for medical conditions?
No, these formulas are general estimates. If you have medical conditions, medications, pregnancy, or other special circumstances, consult your healthcare provider for personalized weight recommendations.
Using Your Ideal Weight Results
- 📊 Compare All Formulas: Review results from all four formulas. Similar values indicate strong consensus.
- 📏 Check the Range: Your healthy weight likely falls within the BMI-based range, not just at the ideal point.
- 💪 Focus on Body Composition: How you look and feel matters more than a specific weight number.
- ⚖️ Consider Frame Size: Use wrist measurement to determine if you should aim toward the lower or higher end of the range.
- 📈 Set Gradual Goals: If far from ideal weight, aim for 5-10% change initially rather than the full target.
- 🏥 Get Professional Input: Consult a healthcare provider for personalized weight management guidance.