Ideal Weight Calculator
Compare target body weight estimates across four established medical formulas.
Consensus range across all medical formulas.
Formula Breakdown
Medical disclaimer. This calculator is for general information and education only. It is not medical advice, not a diagnosis, and not a substitute for professional care. Ideal-weight formulas come from insurance tables and drug-dosing work of the 1960s and 70s. They produce a single figure where a range is more honest, and they ignore body composition entirely.Speak to a doctor or another qualified clinician about any health decision.Last reviewed .
Frequently Asked Questions
What is the Devine Formula for ideal body weight?
The Devine formula is widely used medically for calculating drug dosages: 50 kg + 2.3 kg per inch over 5 feet for men, and 45.5 kg + 2.3 kg per inch for women.
Why are there multiple ideal weight formulas?
Different medical researchers (Devine, Robinson, Miller, Hamwi) developed models based on different population samples and clinical objectives over time.
Does ideal body weight account for muscle mass?
No. Ideal weight formulas estimate baseline target weight for average bone frame and lean mass. Athletes with high muscle mass may weigh more while remaining healthy.
Which ideal weight formula should I use?
Devine (1974) is the most widely used, originally for drug dosing rather than health. Robinson and Miller are refinements that give slightly lower figures; Hamwi is the oldest and quickest for mental arithmetic. All are height-based regressions that ignore frame size and body composition, so they agree with each other more than they agree with any individual.
Was the Devine formula ever meant to define a healthy weight?
No, and this is the most misunderstood thing about it. Dr B.J. Devine published it in 1974 as a way to scale drug doses — notably gentamicin — to lean body mass. It was never validated against health outcomes, and Devine himself published no supporting data. It survives because it is simple and clinicians kept using it, not because it describes an ideal.
Which formula should I actually use?
For a health target, none of them alone. They disagree by several kilograms at the same height because each was fitted to a different population for a different purpose, and none accounts for frame size, body composition or age. The BMI healthy range of 18.5 to 24.9 is broader and better supported; for a 175 cm adult that is roughly 57 to 76 kg, which comfortably contains all four formula results.
Why do the formulas ignore body composition entirely?
Because they take only height and sex as input. A 180 cm powerlifter and a 180 cm sedentary office worker get an identical target, which is obviously wrong for at least one of them. Muscle is denser than fat, so athletes routinely sit well above their calculated ideal weight while carrying less fat than someone at it. A body fat measurement answers the underlying question far better.
Do these formulas work for short or very tall people?
They degrade at both extremes. All four are defined from five feet upward, and their linear per-inch slope was fitted near average heights, so extrapolating far beyond that range compounds error. Below five feet the formulas can produce values that correspond to an implausible BMI, which is why a BMI range is the safer reference for anyone well outside average height.
The four formulas, and where they came from
Each is a straight line: a base weight at five feet, plus a fixed amount per inch above it. They differ only in those two constants, which is why they diverge more the further you get from average height.
Devine (1974) men 50 + 2.3 kg/in women 45.5 + 2.3 kg/in Robinson (1983) men 52 + 1.9 kg/in women 49 + 1.7 kg/in Miller (1983) men 56.2 + 1.41 kg/in women 53.1 + 1.36 kg/in Hamwi (1964) men 48 + 2.7 kg/in women 45.5 + 2.2 kg/in
Hamwi is the oldest, devised for dietetic counselling and easy to do in your head. Devine came a decade later for drug dosing and became the de facto clinical standard. Robinson and Miller were both published in 1983 as explicit corrections to Devine, fitted to actual measured populations — which is why they sit lower at most heights.
Notice the slopes: Hamwi adds 2.7 kg per inch for men while Miller adds 1.41. At 190 cm that difference alone is more than 10 kg. The spread between formulas is not noise to be averaged away — it reflects genuine disagreement about what the number is for.
Not medical advice. These are dosing and counselling heuristics, not health targets. Discuss any weight goal with a clinician who can account for your body composition, medical history and activity.