Ideal Weight Calculator

Ideal body weight (IBW) is an estimate of what you "should" weigh based on your height and gender. It's calculated using formulas like Hamwi, Devine, Robinson, and Miller - developed for medical purposes (drug dosing, nutrition). These formulas use your height and add weight based on gender differences in bone/muscle mass. However, IBW doesn't account for body composition, frame size, or muscle mass.

Not exactly. "Ideal weight" is a specific number from formulas. "Healthy weight" is a range based on BMI (18.5-24.9). You can be healthy at different weights within that range. For a 5'7" woman, ideal weight might be 135 lbs, but healthy range is 118-159 lbs. Both are useful - ideal weight is a target, healthy range is flexibility. Focus on the range, not one number!

Each formula was developed using different populations and purposes. Hamwi (1964) for drug dosing. Devine (1974) for gentamicin dosing. Robinson and Miller refined earlier formulas. They use slightly different multipliers based on their research data. Differences are usually 5-10 lbs. This is why we show the average - it's more reliable than any single formula.

No! This is the biggest limitation. A muscular athlete may weigh 20-30 lbs more than "ideal weight" but have 10% body fat. Conversely, someone at "ideal weight" with no muscle may have 30% body fat and poor health. Body composition (muscle vs fat) matters WAY more than weight alone. Use ideal weight as a starting reference, then adjust based on your body fat percentage and fitness level.

Don't panic! These formulas are averages. If you're muscular, you'll weigh more (good!). If you have a large frame, you'll naturally weigh more. If you have a small frame, you might weigh less. Focus on: How do you feel? What's your body fat percentage? Can you do daily activities easily? Are your health markers (blood pressure, cholesterol) good? Weight is just ONE metric of health, not the only one.

Not necessarily! Use it as a general target, not an absolute goal. If you're within your healthy BMI range (18.5-24.9), feel good, and have good health markers, you're fine regardless of "ideal weight." Focus on body composition: Can you see muscle definition? Do you feel strong and energetic? Those matter more than matching a formula from the 1960s.

Body frame (small, medium, large) can shift ideal weight by 10-15 lbs! Measure wrist circumference: Men - small <6.5", medium 6.5-7.5", large >7.5". Women - small <5.5", medium 5.5-6.5", large >6.5". Large frame people can weigh 10-15 lbs more than calculated ideal weight. Small frame people might weigh 10 lbs less. These calculators assume medium frame.

Neither is perfect! BMI gives you a healthy range (more flexible). Ideal weight gives you a specific target (more precise but rigid). BMI doesn't account for muscle either. Best approach: Use both! Check if your ideal weight falls within your healthy BMI range. If yes, that's a good target. But ultimately, body fat percentage and how you feel are better indicators than either number.

The formulas don't account for age, but your healthy weight can change. As you age, you naturally lose muscle (sarcopenia) unless you strength train. Some weight gain (5-10 lbs) in your 50s-60s is actually associated with better longevity than staying at your 20s weight. Focus on maintaining muscle mass through strength training rather than chasing your "college weight." Health > arbitrary numbers!

Body composition, 100%! You can be at "ideal weight" with 30% body fat (skinny fat) and unhealthy. Or weigh 20 lbs more with 15% body fat, lots of muscle, and be super healthy. Example: A 5'9" man with ideal weight 160 lbs but sedentary vs 180 lbs with muscle - the 180 lb person is healthier! Focus on building muscle and losing fat, not just losing weight. The scale doesn't tell the whole story.