Ideal Weight
4 evidence-based formulas
"Ideal weight" is more of a clinical construct than a fixed number. Several formulas have been published over the decades — Devine (1974), Robinson (1983), Miller (1983), and Hamwi (1964) — and each gives a slightly different answer. The most useful approach is to look at all four and treat the range, not any single number, as the rough target.
This calculator shows all four, side by side, for the same height and sex inputs.
What it shows
- Ideal weight per the Devine formula (most widely used in pharmacy and medicine).
- Ideal weight per Robinson.
- Ideal weight per Miller.
- Ideal weight per Hamwi.
The four results usually agree within a few kilograms.
The formulas
All four start from height in inches above 5 feet. For a person 5'10" (70"), that is 10 extra inches.
- Devine: Men 50 + 2.3 × inches over 5'; Women 45.5 + 2.3 × inches over 5' (kg)
- Robinson: Men 52 + 1.9 × inches over 5'; Women 49 + 1.7 × inches over 5' (kg)
- Miller: Men 56.2 + 1.41 × inches over 5'; Women 53.1 + 1.36 × inches over 5' (kg)
- Hamwi: Men 48 + 2.7 × inches over 5'; Women 45.5 + 2.2 × inches over 5' (kg)
Worked example
A man, 5'10" (10 inches over 5 feet):
- Devine:
50 + 2.3 × 10 = 73 kg ≈ 161 lb - Robinson:
52 + 1.9 × 10 = 71 kg ≈ 157 lb - Miller:
56.2 + 1.41 × 10 = 70.3 kg ≈ 155 lb - Hamwi:
48 + 2.7 × 10 = 75 kg ≈ 165 lb
Range: roughly 155–165 lb. A reasonable healthy weight target falls somewhere in that band.
When to use this
As a directional starting point when setting a weight target. Useful alongside BMI and body fat percentage for a more complete picture. Clinicians sometimes use these formulas for medication dosing (especially Devine) — that is a separate use case from the personal health one.
Caveats
These formulas were derived decades ago, mostly from non-athletic adult populations. They do not account for body composition or frame size. A muscular person may be heavier than the calculated "ideal" while being clearly healthy. Always interpret in context.
Frequently asked questions
Which formula is "right"?
None is uniquely right — all are reasonable estimates. Take the range across all four as a directional target rather than treating any single number as the goal.
Does the result vary by frame size?
These formulas do not directly account for frame size. Smaller-framed individuals may be slightly under the calculated weight, larger-framed slightly over, both at the same body composition.
Is "ideal" the same as "healthy"?
Not exactly. The formulas predict a weight associated with low mortality in mid-twentieth-century data. A healthy weight today is best assessed by a clinician using multiple indicators.