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BMI Calculator

Calculate your Body Mass Index (BMI) instantly using metric or imperial units. Find out if you're in a healthy weight range and see what BMI category you fall into — underweight, normal, overweight, or obese.

Body Mass Index (BMI) Calculator
Your BMI
0.0
Underweight
< 18.5
Normal
18.5 – 24.9
Overweight
25 – 29.9
Obese
≥ 30
BMI –
BMI Value
Category
Healthy Weight Range
Weight to Lose/Gain

BMI Categories & Healthy Weight Range

BMI (Body Mass Index) is a widely used screening tool to categorise weight relative to height. It is calculated by dividing your weight in kilograms by the square of your height in metres (kg/m²). Here are the standard adult BMI categories used by the WHO and CDC:

BMI RangeCategoryHealth Risk
Below 18.5UnderweightNutritional deficiency, low bone density
18.5 – 24.9Normal weightLowest risk — healthy range
25.0 – 29.9OverweightIncreased risk of heart disease, diabetes
30.0 – 34.9Obese (Class I)High risk
35.0 – 39.9Obese (Class II)Very high risk
40.0 and aboveObese (Class III)Extremely high risk

Healthy Weight Reference by Height

HeightHealthy Weight (BMI 18.5–24.9)
150 cm (4'11")41.6 – 56.1 kg (92 – 124 lbs)
160 cm (5'3")47.4 – 63.8 kg (104 – 141 lbs)
170 cm (5'7")53.5 – 72.0 kg (118 – 159 lbs)
175 cm (5'9")56.7 – 76.4 kg (125 – 168 lbs)
180 cm (5'11")59.9 – 80.7 kg (132 – 178 lbs)
185 cm (6'1")63.3 – 85.2 kg (140 – 188 lbs)
190 cm (6'3")66.8 – 90.0 kg (147 – 198 lbs)

Frequently Asked Questions

A healthy BMI for adults is between 18.5 and 24.9. A BMI below 18.5 is considered underweight, 25–29.9 is overweight, and 30 or above is classified as obese. These ranges are the same for both men and women, though BMI doesn't account for muscle mass, age, or body fat distribution.
BMI is calculated by dividing your weight (in kg) by the square of your height (in metres): BMI = weight ÷ height². For imperial units, use: BMI = (weight in lbs × 703) ÷ (height in inches)². For example, someone who is 175 cm and weighs 70 kg has a BMI of 70 ÷ (1.75²) = 22.9.
BMI is a useful population-level screening tool but has limitations for individuals. It doesn't distinguish between muscle and fat — a very muscular person may have a high BMI without excess body fat. It also doesn't account for age, sex, ethnicity, or where fat is distributed on the body. For a more complete picture, consider waist circumference or body fat percentage alongside your BMI.