Ideal Weight Calculator
Find your ideal body weight according to several medical formulas (Devine, Hamwi, Robinson, Miller). Useful as a reference range, especially for medication dosing.
How to use the Ideal Weight Calculator
- Enter your inputs into the Ideal Weight Calculator above.
- Results update instantly as you type — no submit button needed.
- Adjust any value to see how the result changes in real time.
The IBW formulas
Devine men: 50 kg + 2.3 × (height in − 60) · · · Hamwi men: 48 kg + 2.7 × (height in − 60) · · · Women: similar with smaller base weight
Multiple competing formulas exist because no single equation captures the population perfectly. Most produce a 5–10 kg range for the same height.
Worked example
A 5'10" (70-inch) man by Devine: 50 + 2.3 × 10 = 73 kg (161 lb). By Hamwi: 48 + 2.7 × 10 = 75 kg (165 lb). The healthy weight *range* by BMI 18.5–24.9 at this height is roughly 58–82 kg (128–180 lb) — much wider.
Frequently asked questions
Is "ideal weight" really ideal?
It's an estimate, not a target. Medical formulas were developed for purposes like medication dosing, not lifestyle goals. Healthy weight is a range, not a single number, and depends heavily on body composition and individual factors.
Should I aim for IBW?
Not strictly. A healthy BMI range (18.5–24.9) is wider and equally medically valid for most adults. Body fat percentage and waist circumference often matter more than the specific weight number.
Why do the formulas disagree?
Each was derived from different populations using different methods. The 5–10 kg spread between formulas reflects honest uncertainty about what 'ideal' means at a given height.