Ideal Weight Calculator

Choose male or female and enter your height in centimetres. The tool converts your height to inches over 5 feet and runs three ideal-body-weight formulas, plus a weight range based on BMI:

• Devine, highlighted at the top.
• Robinson and Hamwi, side by side below it.
• The weight range that gives a BMI of 18.5 to 24.9 at your height.

For the default man at 175 cm the results are 70.5 kg (Devine), 68.9 kg (Robinson), 72.0 kg (Hamwi) and a BMI range of 56.7 to 76.3 kg. Each formula gives a single reference weight. None of them is a health assessment, and the figures are estimates, not a diagnosis.

Each formula starts from a base weight at 5 feet (152.4 cm) and adds a fixed amount for every inch above it. As they are widely published:

Inches over 5 feet are height (cm) ÷ 2.54 − 60; at 175 cm that is 8.9 inches. These formulas are generally described as having been built for working out drug doses, not to define a healthy weight, which is worth keeping in mind when you read the result.

At 165 cm, height is 4.96 inches over 5 feet. The tool gives:

• Devine: 45.5 + 2.3 × 4.96 = 56.9 kg
• Robinson: 49 + 1.7 × 4.96 = 57.4 kg
• Hamwi: 45.5 + 2.2 × 4.96 = 56.4 kg
• BMI 18.5 to 24.9 range: 50.4 to 67.8 kg

The three formulas land within about a kilogram of each other here, while the BMI range spans more than 17 kg. That contrast is the main thing to take from the page: the single figures look precise, but the range of weights considered healthy by BMI is wide.

The formulas only add weight for height above 5 feet; they have no rule for going below it. The tool sets the inches to zero for anyone shorter, so every result is just the base weight. A woman at 150 cm gets 45.5 kg from Devine, 49 kg from Robinson and 45.5 kg from Hamwi, the same as she would at 152 cm. The BMI range still scales with height (41.6 to 56.0 kg at 150 cm), which makes it the more useful line for shorter adults.