Ideal Body Weight Calculator
Compare Devine, Robinson, Miller, and Hamwi formulas side by side from your height alone.
Your Details
4 formulas compared
Awaiting your height
Enter your gender and height to see 4 formulas side by side.
Why There Are Multiple IBW Formulas
Ideal body weight (IBW) formulas were originally developed for medical dosing (estimating drug doses based on body size), not as fitness or aesthetic targets. Several formulas exist because different researchers built them from different population samples between 1964 and 1983.
| Formula | Year | Origin |
|---|---|---|
| Hamwi | 1964 | Devised for quick clinical estimates |
| Devine | 1974 | Originally for drug dosing calculations |
| Robinson | 1983 | Revision of Devine using updated data |
| Miller | 1983 | Another Devine revision, slightly different constants |
The Formulas (Men)
Devine: 50 + 2.3 kg per inch over 5 feet
Robinson: 52 + 1.9 kg per inch over 5 feet
Miller: 56.2 + 1.41 kg per inch over 5 feet
Hamwi: 48 + 2.7 kg per inch over 5 feet
The Formulas (Women)
Devine: 45.5 + 2.3 kg per inch over 5 feet
Robinson: 49 + 1.7 kg per inch over 5 feet
Miller: 53.1 + 1.36 kg per inch over 5 feet
Hamwi: 45.5 + 2.2 kg per inch over 5 feet
Worked Example
A man who is 180 cm tall (70.9 inches, 10.9 inches over 5 feet):
Devine: 50 + (2.3 x 10.9) = 75 kg
Robinson: 52 + (1.9 x 10.9) = 73 kg
Miller: 56.2 + (1.41 x 10.9) = 71 kg
Hamwi: 48 + (2.7 x 10.9) = 77 kg
The four formulas land within about 6 kg of each other here, which is typical. None of them account for muscle mass, frame size, or body composition.
What IBW Doesn't Tell You
These formulas were never meant to be personal targets. A muscular athlete can weigh well above their "IBW" while carrying very little fat, and someone at their exact IBW number could still have an unhealthy body composition. For a more complete picture, pair this with your Lean Body Mass or Body Fat %.
Frequently Asked Questions
Which IBW formula is most accurate?
None is definitively "most accurate" since they were built for different purposes and populations. Most clinicians treat the average of a few formulas as a reasonable general reference range, not a precise target.
Should I try to weigh exactly my IBW?
Not necessarily. These formulas don't account for muscle mass or frame size. Body composition (how much of your weight is muscle vs. fat) matters more for health than hitting a specific number from a 1960s-1980s formula.
Why do the formulas only need height, not weight?
IBW formulas estimate a target weight FROM height, which is why your current weight isn't an input. They're solving for what weight should be, not evaluating the weight you already have.
Get your lean body mass instead
A body-composition-aware alternative to a height-only estimate.