BMI Calculator
Instant results as you type.
A BMI calculator estimates whether your weight is in a healthy range for your height, using the Body Mass Index — your weight in kilograms divided by your height in metres squared. You can enter your measurements either way: kilograms and centimetres, or pounds with feet and inches, and the conversion happens before the formula does. The World Health Organization uses BMI bands to flag underweight, normal, overweight, and obese ranges. It's a quick screening number, not a full health check, and it runs entirely on your device.
How to use it
- Choose your units — kilograms and centimetres, or pounds with feet and inches. Your region is picked for you on the first visit and remembered after you change it.
- Enter your weight and height. Your BMI and its category appear instantly.
- Compare against the WHO bands shown to see where you fall.
Examples
- 70 kg at 175 cm → BMI 22.86 (Normal weight).
- The same body in imperial — 154 lb at 5 ft 9 in → BMI 22.74 (Normal weight).
- 90 kg at 170 cm → BMI 31.14 (Obese).
Frequently asked questions
- What is a healthy BMI range?
- For most adults the World Health Organization considers a BMI of 18.5 to 24.9 as the normal range. Below 18.5 is underweight, 25 to 29.9 is overweight, and 30 or above is obese. These bands are the same for men and women.
- Is BMI accurate for athletes?
- Not always. BMI can't tell muscle from fat, so very muscular people — athletes, weightlifters — may show a high BMI while carrying little body fat. For them, a body-fat measurement gives a truer picture.
- How is BMI calculated?
- BMI is your weight in kilograms divided by your height in metres, squared. For 70 kg at 1.75 m: 70 ÷ (1.75 × 1.75) = 22.86. If you enter pounds and feet, the calculator converts them to kilograms and metres first and then applies the same formula — there is no separate imperial BMI, only the same number reached from different units.
- Does BMI differ for men and women?
- The BMI formula and the standard adult bands are the same for both. Body composition differs between sexes, so BMI is best treated as a general screening tool rather than a precise measure of health.