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Find your healthy weight range using 4 medical formulas
Enter your height and gender to calculate your ideal weight using four established medical formulas. Remember: ideal weight is a range, not a single number, and body composition matters more than the number on the scale.
Enter your details below and click Calculate to see your results.
Ideal weight is not a single number — it's a range that varies depending on the formula used, your body frame, muscle mass, and individual factors. The four medical formulas (Devine, Robinson, Miller, and Hamwi) were developed for different purposes and often give different results for the same person. This variation is normal and reflects the fact that there's no single 'perfect' weight for any given height. Instead of fixating on one number, focus on the range between the lowest and highest formula results. Your ideal weight likely falls somewhere within this range, depending on your body composition, frame size, and health goals.
The Devine formula (1974) is the most commonly used in clinical settings and was originally developed for drug dosing calculations. The Robinson formula (1983) is a slight modification of Devine that tends to give slightly higher weights. The Miller formula (1983) takes a different approach and often produces results in the middle of the range. The Hamwi formula (1964) is used in clinical nutrition and tends to give weights on the lower end. Each formula has its strengths and was developed for specific medical applications, which is why they can produce different results. None is definitively 'better' than the others — they simply represent different approaches to estimating healthy weight ranges.
While these formulas provide useful reference points, your health and fitness are determined by much more than the number on the scale. Body composition — the ratio of muscle to fat — is far more important than total weight. A muscular athlete might weigh more than the 'ideal' range but have excellent health markers, while someone within the ideal range might have poor body composition. Focus on building lean muscle mass, maintaining healthy body fat levels, eating a balanced diet, staying active, and monitoring health markers like blood pressure, cholesterol, and energy levels. These factors are much better indicators of health than whether you fall within a specific weight range.
Use your ideal weight range as a general reference point, not a strict target. If you're significantly above the range and want to lose weight, focus on sustainable fat loss through a moderate calorie deficit, strength training, and adequate protein intake to preserve muscle mass. If you're below the range and want to gain weight, aim for lean muscle gain through resistance training and a slight calorie surplus with plenty of protein. If you're within the range but unhappy with your body composition, consider body recomposition — building muscle while losing fat. Remember that healthy weight loss is 0.5-1 kg (1-2 lbs) per week, and healthy weight gain is 0.25-0.5 kg (0.5-1 lb) per week.
Sarah is a 28-year-old female who stands 5'6" (168 cm). She wants to understand her ideal weight range to set realistic health goals.
Sarah's ideal weight range is 56.6-58.9 kg (125-130 lbs) based on the four medical formulas. The average across all formulas is 57.7 kg (127 lbs). This 3.3 kg range shows why ideal weight isn't a single number — different formulas give different results, all of which can be considered healthy. If Sarah currently weighs 65 kg and wants to lose weight, she could aim for somewhere within this range. However, if she's active and carries significant muscle mass, she might be perfectly healthy at a higher weight. The key is focusing on body composition, health markers, and how she feels rather than hitting an exact number.
Common questions about this calculator and how to use your results.
Each formula was developed for different purposes and uses slightly different calculations. The Devine formula was created for drug dosing, Robinson for clinical applications, Miller as an alternative approach, and Hamwi for nutrition counseling. These different origins and methodologies naturally lead to variations in results. This variation is actually helpful because it shows that ideal weight is a range, not a single number.
No single formula is definitively more accurate than others because 'ideal weight' varies based on individual factors like body frame, muscle mass, and genetics. The Devine formula is most commonly used in medical settings, but all four formulas provide valid reference points. Rather than choosing one formula, it's better to consider the range between the lowest and highest results as your healthy weight range.
Being outside the calculated range doesn't automatically mean you're unhealthy. These formulas don't account for muscle mass, bone density, or body frame. If you're above the range but have good body composition and health markers, you may be perfectly healthy. If you're concerned, focus on improving body composition through strength training and proper nutrition rather than just losing weight. Consult a healthcare provider for personalized advice.
Muscle is denser than fat, so people with more muscle mass will naturally weigh more than the calculated ideal range while still being healthy. Athletes and people who strength train regularly often weigh more than these formulas suggest because the formulas don't distinguish between muscle and fat. This is why body composition (muscle-to-fat ratio) is more important than total weight for health and appearance.
Neither — aim for somewhere in the middle of your range, but more importantly, focus on body composition rather than a specific number. If you're naturally larger-framed or carry more muscle, you might be healthiest at the higher end of the range. If you're smaller-framed, you might feel best at the lower end. The key is finding a weight where you feel strong, energetic, and healthy while maintaining good body composition.
Your ideal weight range doesn't change unless your height changes (which only happens significantly during growth periods). Once you know your range, you don't need to recalculate it regularly. Instead, focus on tracking body composition, strength, energy levels, and health markers. Weigh yourself consistently (same time of day, same conditions) if you find it helpful, but remember that daily weight fluctuations are normal and don't reflect true changes in body composition.
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