Ideal Weight Calculator (Devine, Robinson, Miller)
Compare ideal body weight estimates from the Devine, Robinson, Miller, and Hamwi formulas alongside the healthy BMI range for your height.
Ideal body weight formulas
Several formulas estimate a "target" weight from height alone. They all share the same shape: a base weight at five feet, plus a fixed amount for every inch above that. They differ only in the constants, which is why they disagree — and why no single one is authoritative.
Devine (men): 50 kg + 2.3 kg per inch over 5 ft
Devine (women): 45.5 kg + 2.3 kg per inch over 5 ft
Where they came from
The Devine formula wasn't designed for health advice at all — it was created in 1974 to calculate medication doses, and it's still used that way in clinical pharmacy. Robinson andMiller refined it against insurance data, and Hamwi came out of diabetes care in 1964. None was built as a personal weight target, which is worth remembering when the numbers disagree by several kilograms.
Why the healthy BMI range is more useful
Every one of these formulas produces a single number, which is misleading — healthy weight is a range, not a point. The BMI range shown alongside (18.5–24.9) is usually the more sensible reference, and it's typically wide enough to contain all four formula results.
Worked example
A man 175 cm tall is 8.9 inches over five feet. Devine gives 50 + 2.3 × 8.9 ≈ 70.5 kg; Robinson about 68.9 kg; Miller about 68.7 kg; Hamwi about 72.0 kg. A spread of over 3 kg from the same height — while the healthy BMI range for that height spans roughly 56.7 to 76.3 kg.
These are rough population formulas, not medical advice.They take no account of body composition, frame size, age, or health status, and none of them should be treated as a personal goal. Speak to a doctor or dietitian about what's appropriate for you.
These are population formulas, and they disagree
Devine, Robinson, Miller and Hamwi were all derived by fitting curves to measurements of large groups, and they give different answers for the same person — sometimes by several kilograms. That spread is shown deliberately, because it is more informative than any single number would be. None of them accounts for build, muscle mass, or body composition, and the original purpose of several was drug dosing rather than describing a healthy weight.Treat the range as a rough reference point, not a target, and take questions about your own weight to a clinician.