Health
Ideal Weight Calculator
See the ideal body weight your height suggests under four established clinical formulas, side by side as a range.
Calculation inputs
Frame size is optional and adjusts the range by roughly 10% either way.
Results
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Estimates only, for general information. Not medical advice.
About this calculator
This calculator shows the ideal body weight your height suggests under four long-used clinical formulas, presented side by side as a range. It is a reference tool built originally for medication dosing, not a body-image target.
How the calculation works
- Devine: 50 kg (men) or 45.5 kg (women) + 2.3 kg per inch over 5 feet
- Robinson: 52 kg (men) or 49 kg (women) + 1.9/1.7 kg per inch over 5 feet
- Miller: 56.2 kg (men) or 53.1 kg (women) + 1.41/1.36 kg per inch over 5 feet
- Hamwi: 48 kg (men) or 45.5 kg (women) + 2.7/2.2 kg per inch over 5 feet
Notes and assumptions
These formulas were built for medication dosing and clinical reference, not as body-image targets — they ignore muscle mass and body composition entirely.
How it works in plain English
Each formula starts from a base weight for someone at exactly 5 feet tall and adds a fixed amount for every inch above that, with separate figures for men and women. The Devine, Robinson, Miller, and Hamwi formulas all follow this same basic shape but use slightly different base weights and per-inch amounts, which is why they produce a range rather than one single number.
The calculator computes all four formulas from your entered height and gender, converts each result from kilograms to pounds, and reports the lowest and highest values as your range, along with an average across all four. If you select a frame size, the whole range shifts down about 10% for a small frame or up about 10% for a large frame, since these formulas were originally built around an assumed medium frame.
Because these formulas only use height and gender, they cannot account for muscle mass, bone density, or overall body composition, which is why they are best treated as a rough historical reference rather than a personal target.
The formula
- Devine = 50 kg (men) or 45.5 kg (women) + 2.3 kg per inch over 5 feet
- Robinson = 52 kg (men) or 49 kg (women) + 1.9/1.7 kg per inch over 5 feet
- Miller = 56.2 kg (men) or 53.1 kg (women) + 1.41/1.36 kg per inch over 5 feet
- Hamwi = 48 kg (men) or 45.5 kg (women) + 2.7/2.2 kg per inch over 5 feet
Worked example
For a man who is 5'9" (9 inches over 5 feet) with a medium frame, Devine gives 50 + 2.3 x 9 = 70.7 kg (about 156 lb), Robinson gives 52 + 1.9 x 9 = 69.1 kg (about 152 lb), Miller gives 56.2 + 1.41 x 9 = 68.9 kg (about 152 lb), and Hamwi gives 48 + 2.7 x 9 = 72.3 kg (about 159 lb).
Across those four figures the range runs from about 152 lb to 159 lb, with an average of roughly 155 lb, shown alongside each individual formula's result.
The four ideal weight formulas
| Formula | Base (men) | Base (women) | Per inch over 5 ft |
|---|---|---|---|
| Devine | 50.0 kg | 45.5 kg | 2.3 kg |
| Robinson | 52.0 kg | 49.0 kg | 1.9 / 1.7 kg |
| Miller | 56.2 kg | 53.1 kg | 1.41 / 1.36 kg |
| Hamwi | 48.0 kg | 45.5 kg | 2.7 / 2.2 kg |
Formulas follow their original published forms as used in clinical and pharmacological reference contexts.
Frequently asked questions
Which of the four formulas is the most accurate?
None of them is universally more accurate, since each was developed for a slightly different clinical purpose, mostly around estimating dosing weight rather than describing a healthy body weight. Looking at the range and average across all four gives a broader sense of where the estimates land than trusting any single one.
Why do these formulas ignore muscle and body fat?
They were designed decades ago as quick reference calculations based only on height and gender, before body composition tools were common in everyday use. As a result, a muscular person can fall well outside the range these formulas suggest without that indicating anything unhealthy.
What does the frame size adjustment actually do?
Selecting a small or large frame shifts the entire calculated range down or up by about 10%, reflecting the idea that people with smaller or larger bone structure carry proportionally different healthy weights. It's a rough adjustment layered on top of the four base formulas, not a separate measurement of your actual frame.
Is this the same as a healthy weight range from a BMI calculator?
No, these formulas and BMI-based ranges are calculated differently and can produce different numbers for the same height. Both are general reference tools based on population averages, so neither should be treated as a precise personal target.
Should I try to reach the exact average shown?
The average is just a midpoint across four historical formulas and isn't a specific goal to aim for. Overall health depends on many factors beyond a single weight number, so it's worth checking with a qualified professional before setting any weight-related goal.