Body Mass Index
Enter your height and weight to get your body mass index and what it means for your health.
Enter your height and weight,
then hit Calculate.
BMI is a screening tool, not a diagnosis. It does not account for muscle mass, bone density, age, or distribution of fat. Consult a healthcare professional for a full assessment.
This free BMI calculator works out your Body Mass Index from your height and weight. It shows your BMI number, your category, the weight range that matches a healthy BMI for your height, and general health guidance. You can use metric (cm and kg) or imperial (feet, inches and pounds).
BMI is a simple screening tool. It is a starting point for a conversation about health, not a medical diagnosis.
Example: a person who weighs 70 kg and is 170 cm (1.70 m) tall has a BMI of 70 ÷ (1.70 × 1.70) = 70 ÷ 2.89 = 24.2, which is in the healthy range. For the same height, a BMI between 18.5 and 24.9 matches a weight of about 53.5 to 72.0 kg.
BMI (Body Mass Index) is a number calculated from your weight and height. It is a quick screening tool that places adults into groups such as underweight, healthy weight, overweight and obese.
For adults, a BMI from 18.5 to 24.9 is considered the healthy weight range. Below 18.5 is underweight, 25 to 29.9 is overweight, and 30 or above is in the obese range.
BMI is useful for looking at groups of people, but it has limits for individuals. It does not measure body fat directly and cannot tell muscle from fat. A muscular person can have a high BMI without having excess fat, and some people with a normal BMI can still carry extra body fat.
The formula and the adult categories are the same for men and women. Women often have a higher body fat percentage than men at the same BMI, so a body fat measurement can add useful detail.
The categories shown here are for adults aged 20 and over. For children and teenagers, doctors compare BMI with growth charts for their age and sex, so please ask a healthcare professional. The age box on this page is optional and does not change the BMI result.
A BMI outside the healthy range is a reason to look at the bigger picture, not a diagnosis. A doctor can consider your health, waist size, family history and lifestyle. Speak to a healthcare professional before making big changes to your diet or exercise.
Disclaimer: This calculator is for general information only and is not medical advice. BMI does not consider muscle mass, bone density, age or fat distribution. Consult a healthcare professional for a full assessment.