Ideal Weight Calculator

No single formula is definitively "most accurate" because all four (Devine, Robinson, Miller, Hamwi) were derived from different population samples decades ago and none account for individual muscle mass, bone density, or frame variation directly. Devine (1974) is the most widely used in clinical medicine, particularly for drug dosing calculations. Robinson (1983) and Miller (1983) are modified versions that tend to produce slightly different results, with Miller generally giving somewhat higher values for lighter frames. Rather than picking one as "correct," this calculator averages all four to reduce the impact of any single formula's quirks and give you a more balanced reference range.

Each formula was developed by different researchers using different reference populations and slightly different mathematical relationships between height and weight. Devine was originally created for medication dosing purposes (not as a general "ideal weight" concept) and has since been repurposed broadly. Robinson and Miller are later refinements aiming to improve on Devine's original coefficients. Hamwi, developed in 1964, is one of the oldest and simplest. The spread between formulas for a given height is usually only 3–6 kg, which is why averaging across all four provides a more stable, representative estimate than relying on any one formula alone.

They are dated (all developed between 1964 and 1984) but remain in active clinical and practical use today, primarily because they are simple, require only height and sex, and provide a reasonable general reference point. Their key limitation is that none of them account for body composition — muscle mass, bone density, or fat distribution — which is why they should be treated as a general reference range rather than a precise individual target. Modern practice generally recommends pairing ideal weight estimates with BMI and, ideally, body fat percentage for a fuller picture.

Yes, if you know it — frame size (based on wrist circumference relative to height, or simply visual assessment of bone structure) provides a useful adjustment since people with larger skeletal frames and broader shoulders/hips can healthily carry more weight at the same height than someone with a smaller frame. This calculator applies a ±9% adjustment for small and large frames relative to the medium-frame baseline. If you're unsure of your frame size, a rough guide is: wrap your thumb and middle finger around your wrist — if they overlap significantly, you likely have a small frame; if they just touch, medium; if they don't meet, likely a large frame.

Not necessarily. "Ideal weight" formulas produce a population-average reference point based purely on height (and frame size, sex), but your genuinely healthiest weight depends on additional factors these formulas can't see: your muscle mass, body fat percentage, metabolic health markers (blood pressure, blood sugar, cholesterol), and how you feel and function at a given weight. Someone with substantial muscle mass from years of strength training may have a healthiest weight considerably above their "ideal weight" formula result, while still being in excellent metabolic health. Use these formulas as a general reference point, not a rigid target to chase regardless of your actual body composition.

All four formulas include separate coefficients for men and women, reflecting average physiological differences in body composition — men typically carry more muscle mass and less essential body fat than women at the same height, which is baked into each formula's constants. This is similar to how BMI's healthy range doesn't differentiate by sex but body fat percentage healthy ranges do — ideal weight formulas sit in between, adjusting for average sex-based body composition differences while still using a single height-weight relationship.

Athletes and muscular individuals should treat their ideal weight calculator result with considerable caution, for the same reason BMI misleads for this population — none of these formulas account for muscle mass. A muscular athlete will very likely weigh meaningfully more than their "ideal weight" result while being in excellent health, simply because they carry more lean tissue than the formulas' reference populations. For athletes, body fat percentage (via our Body Fat Calculator) and performance-based health markers are far more informative than any height-based ideal weight formula.

Ideal weight formulas and BMI both use height as an input but calculate things differently — BMI is a ratio (weight ÷ height²) with fixed universal category boundaries, while ideal weight formulas produce an absolute weight figure (in kg or lbs) for your specific height. In practice, the "ideal weight" figures from these formulas typically correspond to a BMI in the 21–23 range, comfortably within the "normal weight" BMI category (18.5–24.9), which is why the two approaches are broadly consistent even though they're calculated differently.

Not necessarily as a rigid target. Treat the result as a general reference range (especially since this calculator averages four formulas, giving you a spread rather than one number) rather than a precise target you must hit. If your current weight sits within a reasonable range of this estimate and your health markers (blood pressure, energy levels, physical function) are good, there's little value in obsessively chasing an exact number. If your current weight is substantially outside the range and you have other risk factors (elevated blood pressure, high waist circumference, or poor metabolic markers), it's a reasonable general direction to work toward through sustainable lifestyle changes.

These formulas are all linear extrapolations from a baseline height (5 feet / 152.4 cm), adding a fixed amount of weight per inch above that baseline. This linear approach works reasonably well across typical adult height ranges but becomes progressively less reliable at height extremes (very tall individuals over 200cm, or very short individuals under 150cm), since human body proportions don't scale in a perfectly linear way at the extremes. If you're at either end of the height spectrum, treat the result as a rougher approximation and lean more heavily on BMI and body fat percentage for a fuller individual picture.

These specific formulas do not incorporate age directly — they were designed as general adult reference values. In practice, though, healthy body composition does shift somewhat with age: older adults typically carry a slightly higher proportion of body fat at the same total weight due to age-related muscle loss (sarcopenia), meaning the "ideal weight" figure from these formulas may represent a somewhat different body composition in a 25-year-old versus a 65-year-old, even though the target number itself is the same. This is another reason to treat the output as a general reference range rather than a precise clinical target.

First, consider your body composition and frame — a large gap could partly reflect above-average muscle mass or frame size rather than excess fat, especially if you train regularly. Check your BMI and, ideally, your body fat percentage for a fuller picture before concluding you need to change your weight significantly. If those additional measures do suggest genuine excess weight, use our TDEE Calculator to find your maintenance calories and set a sustainable 300–500 kcal/day deficit, combined with resistance training to preserve muscle mass, working gradually toward a healthier range rather than trying to hit the exact number quickly.