Ideal Weight Calculator
Estimate reference body weight using four established formulas — Devine, Robinson, Miller, and Hamwi. Enter height and sex to see each formula's estimate in kg and lb.
Calculator Inputs
Enter your height as a single number matching the unit selected below. In US units, enter TOTAL inches (e.g. 5'9" = 69 in), not separate feet and inches.
Each formula below uses different constants for male and female.
- Devine Formula (kg)
- 70.46
- Devine Formula (lb)
- 155.35
- Robinson Formula (kg)
- 68.91
- Robinson Formula (lb)
- 151.91
- Miller Formula (kg)
- 68.75
- Miller Formula (lb)
- 151.56
- Hamwi Formula (kg)
- 72.30
- Hamwi Formula (lb)
- 159.39
- Note
About these results
CalcSpectrum calculators produce automated estimates using established formulas and the specific values you enter. Because real-world outcomes depend on input accuracy, mathematical assumptions, and rounding conventions, please verify critical figures with an appropriately qualified financial, tax, medical, legal, or other professional, as relevant.
Health & Fitness Notice: Wellness and body metric calculations provide informational estimates based on generalized population formulas. They do not provide medical diagnosis, clinical advice, or treatment plans. Consult an appropriately qualified medical or healthcare professional for personal guidance.
How It's Calculated
Formula
This calculator reports four established, formula-derived reference weight estimates — Devine (1974), Robinson (1983), Miller (1983), and Hamwi (1964) — shown individually rather than averaged into one number. Each formula gives a base weight at 5 feet (60 inches) of height and adds a fixed amount per inch above that, with separate constants for male and female. These are reference estimates from published equations, not a prescribed or medically required target weight for any individual — the four formulas routinely disagree with each other by several kilograms for the same height, which itself shows none of them is a single ground truth. All four formulas were originally calibrated for adult heights at or above 5 feet; entering a shorter height still produces a number (the same linear formula, extrapolated), but that figure falls outside the formulas' original reference range and is flagged accordingly. This is an estimate for general informational and educational purposes, based on a published formula — it is not a medical diagnosis, and it is not a substitute for individualized advice from a qualified healthcare provider. None of these formulas account for frame size, muscle mass, or individual body composition.
Worked Examples
Male, 70 in (5'10")
- Inches over 60: 70 − 60 = 10
- Devine: 50.0 + 2.3 × 10 = 73.0 kg
- Robinson: 52.0 + 1.9 × 10 = 71.0 kg
- Miller: 56.2 + 1.41 × 10 = 70.3 kg
- Hamwi: 106 + 6 × 10 = 166 lb ≈ 75.3 kg
Frequently Asked Questions
Which of the four formulas is correct?
None is uniquely "correct" — they're four independently published equations that estimate reference weight differently, and they routinely disagree by several kilograms for the same person. Showing all four side by side, rather than averaging them into a single number, is more honest than picking one (or blending them) and presenting the result as definitive.
Is this my ideal weight target?
No. These are formula-derived reference estimates from decades-old equations originally developed for medication dosing and general reference, not an individualized target set by a healthcare provider. They don't account for muscle mass, frame size, or your specific health situation.
What happens if I enter a height under 5 feet?
The calculator still computes a result using the same linear formulas, extrapolated below their original 60-inch calibration floor. A note appears on the result flagging that the figure is outside the formulas' original reference range.
Why does sex change the result?
All four formulas use separate base weights and per-inch constants for male and female, reflecting the average body-composition differences the original equations were derived from.