Ideal Weight Calculator

How It Works

This tool runs four published height-based weight formulas side by side, because "ideal weight" is honestly a range, not a single number. All math is done in metric (cm and kg) and converted to pounds for display.

The Four Formulas

Each estimates a body weight from height above 5 feet, with separate constants for men and women. Hamwi (1964): men 48 kg + 2.7 kg per inch, women 45.5 kg + 2.2 kg. Devine (1974): men 50 kg + 2.3 kg per inch, women 45.5 + 2.3. Robinson (1983): men 52 + 1.9, women 49 + 1.7. Miller (1983): men 56.2 + 1.41, women 53.1 + 1.36. Devine's version is still the one many drug-dosing references use, which is why it is here even though it is the middle estimate on most heights, not the oldest.

Frame Correction (±10%)

Hamwi's build adjustment — subtract about 10% for a small frame, add about 10% for a large one — is a convention commonly applied to all four formulas, and this tool applies it to all of them. A quick proxy for frame size is wrist circumference measured just below the hand: for men under 16 cm is small, 16–18 cm medium, over 18 cm large; for women the cut-offs are 14 cm and 16 cm.

Why the Spread Is the Point

For the same person the four formulas typically disagree by several kilograms, which is why the highlighted card shows the min–max range across all four rather than crowning a winner. The BMI band (18.5–24.9 × height in metres squared) is included as a fifth, screening-only reference: it answers "medically healthy zone" rather than "ideal", and it misjudges muscular and older bodies in opposite directions.

Frequently Asked Questions