Body Mass Index (BMI) is one of the quickest ways to get a general idea of whether your weight is in a healthy range for your height. It is not a perfect measure, but it is a useful starting point, and it takes less than a minute to calculate.
The BMI formula
BMI = weight (kg) ÷ height (m)²
For example, if you weigh 70 kg and are 1.75 m tall: 1.75 × 1.75 = 3.06, and 70 ÷ 3.06 = 22.9.
BMI categories for adults
- Below 18.5: Underweight
- 18.5 to 24.9: Normal weight
- 25 to 29.9: Overweight
- 30 and above: Obese
Skip the math
If you do not want to calculate by hand, you can use a free BMI calculator that works in kilograms or pounds and gives you the result instantly. If you want to go further, you can also estimate your daily energy needs with a calorie calculator.
Limitations of BMI
BMI does not separate muscle from fat, so athletes can be labelled "overweight" even when they are lean. It also does not account for age, sex, or where fat is stored. Use it as one data point, not a diagnosis.
Tips for a healthier BMI
- Eat mostly whole foods and watch portion sizes.
- Aim for at least 150 minutes of moderate activity per week.
- Sleep 7-8 hours, since poor sleep affects weight.
- Track progress monthly, not daily.
This article is for general information and is not medical advice. Please consult a doctor for personal guidance.
