Ideal Weight Calculator
Calculate your ideal body weight using four popular formulas: Devine, Hamwi, Robinson, and Miller. Plus, get a healthy weight range based on BMI. Understand your optimal weight for better health, fitness, and wellness.
What Is Ideal Weight?
Ideal body weight (IBW) is an estimate of the optimal weight for an individual based on their height and gender. It is used in medical settings for drug dosing, nutritional assessment, and as a general guideline for healthy weight management.
This calculator uses four different formulas, each developed for different purposes:
- Devine Formula (1974): Originally developed for drug dosing, it's now the most widely used IBW formula in medicine. For men: 50 kg + 2.3 kg per inch over 5 feet. For women: 45.5 kg + 2.3 kg per inch over 5 feet.
- Hamwi Formula (1964): A simpler formula developed for quickly estimating ideal weight. For men: 106 lbs + 6 lbs per inch over 5 feet. For women: 100 lbs + 5 lbs per inch over 5 feet.
- Robinson Formula (1983): A refined version of the Devine formula. For men: 52 kg + 1.9 kg per inch over 5 feet. For women: 49 kg + 1.7 kg per inch over 5 feet.
- Miller Formula: An alternative method with a different linear relationship. For men: 56.2 kg + 1.41 kg per inch over 5 feet. For women: 53.1 kg + 1.36 kg per inch over 5 feet.
Understanding BMI-Based Weight Range
The healthy BMI weight range is based on the World Health Organization's classification of normal weight — a BMI between 18.5 and 24.9. This range is calculated by multiplying the square of your height in meters by 18.5 and 24.9.
While the four formulas give a single number, the BMI range provides a healthy weight range that accounts for individual variations in body composition.
Why Use This Ideal Weight Calculator?
- Four Formulas: Compare results from different methods to get a comprehensive view.
- BMI Range: See the healthy weight range based on international standards.
- Flexible Units: Switch between metric and imperial units.
- Visual Comparison: A chart shows how the different formulas compare.
- Educational: See the formula used for each calculation.
- Free & Private: No registration, no data storage.
❓ Ideal Weight Calculator FAQ
What is the most accurate ideal weight formula?
The Devine formula is the most widely used in medical settings for drug dosing and clinical purposes. However, the Robinson formula has been found to be the best equation for calculating desirable/healthy weights in men. For women, BMI ranges may be more useful than IBW formulas.
What is the Devine formula for ideal weight?
The Devine formula is: For men, IBW = 50 kg + 2.3 kg for each inch over 5 feet. For women, IBW = 45.5 kg + 2.3 kg for each inch over 5 feet. It was originally developed for drug dosing calculations.
What is the Hamwi formula for ideal weight?
The Hamwi formula uses pounds and inches: For men, 106 lbs for the first 5 feet + 6 lbs for each additional inch. For women, 100 lbs for the first 5 feet + 5 lbs for each additional inch.
What is the Robinson formula for ideal weight?
The Robinson formula is: For men, 52 kg + 1.9 kg per inch over 5 feet. For women, 49 kg + 1.7 kg per inch over 5 feet. It's a refinement of the Devine formula.
What is the Miller formula for ideal weight?
The Miller formula is: For men, 56.2 kg + 1.41 kg per inch over 5 feet. For women, 53.1 kg + 1.36 kg per inch over 5 feet. It provides an alternative estimate of ideal weight.
What is a healthy BMI range?
A healthy BMI range is between 18.5 and 24.9. This range is associated with the lowest risk of weight-related health problems and is used by the World Health Organization as the standard for normal weight.
How do I calculate my ideal weight range using BMI?
Multiply the square of your height in meters by 18.5 (lower end) and 24.9 (upper end). For example, if you are 1.7 m tall: Lower = 18.5 × 1.7² = 53.5 kg, Upper = 24.9 × 1.7² = 72.0 kg. This calculator does this for you automatically.
Is ideal weight the same as healthy weight?
Ideal weight is a specific calculation based on height and gender. Healthy weight is a broader concept that includes BMI range, body composition, and individual health factors. Your ideal weight should fall within the healthy BMI range for your height.
Do I need to be at my ideal weight?
Ideal weight is a guideline, not a requirement. Focus on maintaining a weight that supports your health, energy levels, and overall well-being. Consult with a healthcare provider for personalized advice.
How does age affect ideal weight?
Most IBW formulas don't include age. However, older adults may benefit from slightly higher BMI ranges (up to 25-27) due to natural changes in body composition. Always consult a healthcare provider for age-specific recommendations.
What is the difference between ideal weight and adjusted body weight?
Ideal weight (IBW) is the estimated optimal weight for height. Adjusted body weight (AjBW) is used in clinical settings for patients who are overweight or obese: AjBW = IBW + 0.4 × (Actual Weight − IBW). This calculator focuses on IBW.
How do I convert my height from feet/inches to centimeters?
1 foot = 30.48 cm, 1 inch = 2.54 cm. For example, 5'7" = (5 × 30.48) + (7 × 2.54) = 152.4 + 17.78 = 170.18 cm. This calculator can handle both units.
What is the Lorentz formula for ideal weight?
The Lorentz formula is an alternative method: Ideal weight (kg) = height in cm - 100 - (height in cm - 150) / 4. It's less commonly used than the Devine, Hamwi, Robinson, and Miller formulas.
How does muscle mass affect ideal weight?
IBW formulas don't account for muscle mass. Athletes and individuals with higher muscle mass may weigh more than their IBW while still being healthy. In these cases, body fat percentage is a better health indicator.
What is the Broca formula for ideal weight?
The Broca formula is a simple method: Ideal weight (kg) = height (cm) − 100. It's easy to remember but less accurate than other formulas and doesn't account for gender or body frame size.
How accurate are ideal weight formulas?
Ideal weight formulas provide estimates and are most useful as general guidelines. They were originally developed for medical dosing and may not account for individual variations in body composition, frame size, or ethnicity.
Can I use this calculator for children?
These formulas are designed for adults. Children and adolescents should use growth charts and pediatric BMI percentiles for weight assessment. Consult a pediatrician for appropriate weight guidance.
What is the best weight for my height?
The best weight for your height depends on many factors including body frame, muscle mass, age, and overall health. Use the healthy BMI range (18.5-24.9) as a starting point and consult a healthcare provider for personalized advice.
How often should I check my ideal weight?
Check your ideal weight whenever your height changes (unlikely in adulthood) or as part of routine health assessments. For weight management, focus on maintaining a healthy weight range rather than a specific number.