How to find your ideal weight range from height

Steps

1. Convert your height to inches: 175 cm ÷ 2.54 = 68.9 inches.
2. Subtract 60 inches (5 feet): 8.9 inches over.
3. Devine for a man: 50 + 2.3 × 8.9 = 70.5 kg. Robinson: 52 + 1.9 × 8.9 = 68.9 kg.
4. For a woman use 45.5 + 2.3 per inch (Devine) or 49 + 1.7 per inch (Robinson).
5. Compare with the healthy BMI range: 18.5 × height² to 24.9 × height², with height in metres.

A worked example for a woman

A woman 162 cm tall is 63.8 inches, which is 3.8 over 5 feet. Devine gives 54.2 kg and Robinson gives 55.4 kg. The healthy BMI range for her height is 48.6 to 65.3 kg.

The formulas give one number each, while the BMI range gives a span. The span is the more useful guide, since healthy bodies come in a range.

Why there are several answers

The Devine and Robinson formulas were made for general guidance, mainly to set medicine doses, not to define a perfect weight. They ignore age, frame size and how much of your weight is muscle. Two people of the same height can be equally healthy at weights that differ by 10 kg or more.

Use it sensibly

Treat the result as a rough reference, and look at how you feel, your fitness and your medical checks. If you are well outside the range, a doctor or dietitian can look at your whole health. This page gives general information, not medical advice.