BMI Calculator (Metric & Imperial)
Enter your height and weight to get your BMI and the corresponding category, with metric and imperial support and a clear note on BMI’s limitations.
Examples
180 cm, 75 kg
BMI 23.1 — Normal weight
How it works
BMI is your weight divided by the square of your height. In metric that is kilograms ÷ metres²; in imperial it is pounds × 703 ÷ inches². The result is shown to one decimal place together with its category.
| BMI | Category |
|---|---|
| Below 18.5 | Underweight |
| 18.5 to 24.9 | Normal weight |
| 25 to 29.9 | Overweight |
| 30 or above | Obese |
In imperial mode, enter height as total inches: 5 ft 10 in is 70. The same ranges apply to adult men and women. They are not meant for children and teenagers, who are assessed against age-based charts, and BMI can overstate body fat in muscular people.
How to use BMI Calculator
Why use this tool
Frequently asked questions
BMI is a rough screening tool. It does not account for muscle mass, age or body composition, so treat it as a guide, not a diagnosis.
BMI = weight in kg ÷ (height in metres)². For 75 kg and 180 cm: 75 ÷ (1.8 × 1.8) = 23.1.
BMI = weight in pounds × 703 ÷ (height in inches)². For 165 lb and 70 in: 165 × 703 ÷ (70 × 70) = 23.7. Enter your height in inches, so 5 ft 10 in is 70.
Under 18.5 is underweight, 18.5–24.9 is healthy weight, 25–29.9 is overweight, and 30 or above is obese (WHO adult ranges).
Found a bug or have an idea?
ToolOrbit is actively developed — feedback directly shapes what gets built next.
Send feedback