Healthy Weight Range for Your Height: How It Is Calculated

From BMI to a weight range

For adults, the World Health Organization labels a BMI from 18.5 up to just below 25 as the healthy (normal) range. BMI is weight divided by height squared, so rearranging gives the weight for any BMI.

weight (kg) = BMI × height (m)²Run it twice: once with 18.5 and once with 24.9 to get the lower and upper ends.

Worked example, 1.70 m: height squared is 1.70 × 1.70 = 2.89. The lower end is 18.5 × 2.89 = 53.5 kg. The upper end is 24.9 × 2.89 = 72.0 kg. The healthy range at this height is about 53.5 to 72 kg.

Using 24.9 keeps the result strictly below the BMI of 25 where the overweight category begins. If you use 25 exactly the upper figure becomes 72.3 kg, which is a trivial difference.

The same calculation in pounds and inches

weight (lb) = BMI × height (in)² ÷ 703Convert feet and inches to inches first.

Worked example, 5 ft 6 in: that is 66 inches, and 66² = 4,356. The lower end is 18.5 × 4,356 ÷ 703 = 114.6 lb. The upper end is 24.9 × 4,356 ÷ 703 = 154.3 lb. So the healthy range at 5 ft 6 in is about 115 to 154 lb.

You can check any height with the healthy weight calculator, and see where your current weight falls with the BMI calculator. The factor 703 is explained in the guide to calculating BMI by hand.

A range for common heights

These ranges use BMI 18.5 to 24.9, rounded to one decimal place in kilograms and to the nearest pound.

Notice how wide each band is. At 170 cm it spans about 18.5 kg. The range is wide because people are built differently, and the BMI bands are designed to be broad.

How ideal weight formulas compare

Ideal weight formulas try to give one number instead of a range. One of the best known is the Devine formula from 1974, which was originally published to help with drug dosing, not to describe a healthy body. It starts from a base weight at 5 feet and adds a fixed amount for every inch above that.

• Men: 50 kg + 2.3 kg for each inch over 5 feet.
• Women: 45.5 kg + 2.3 kg for each inch over 5 feet.

Worked example, 5 ft 6 in (6 inches over 5 ft): for men, 50 + 2.3 × 6 = 63.8 kg. For women, 45.5 + 2.3 × 6 = 59.3 kg. The BMI range for the same height is about 52.0 to 70.0 kg, so both figures land inside it.

Formulas disagree with each other, and none claims to know the best weight for a specific person. The ideal weight calculator shows two of them side by side, which makes the differences easy to see. The healthy range is the more honest message: a band of acceptable weights, not a point.

What the range cannot tell you

• Muscle and build. A muscular person can weigh above the upper end with low body fat. See what BMI can and cannot tell you.
• Where weight sits. Abdominal fat carries more risk, which a waist measurement can show. See waist-to-height and waist-to-hip ratios.
• Ancestry. Where lower BMI cut-offs are used, for example 18.5 to 22.9 for some Asian populations, the upper end at 1.70 m drops from 72 kg to about 66 kg (22.9 × 2.89).
• Age. The adult range does not apply to children and teens. See BMI for children and teens.
• How you feel. Energy, sleep, strength, blood pressure and lab results say a lot more about health than reaching a number on a scale.

This article is general education and not medical advice. A doctor or other qualified health professional can tell you what weight is appropriate for you, taking your age, health history and body composition into account.