BMI Calculator for Adults (Body Mass Index)
Use this free BMI calculator to estimate your Body Mass Index using metric or imperial units. BMI is a quick way to screen for underweight, healthy weight, overweight or obesity in adults. Results are for information only and do not replace medical advice.
Calculate your BMI
Choose your unit system, enter your weight and height, then click “Calculate BMI”.
How to interpret your BMI result
BMI is calculated by dividing your weight by your height squared. It gives a number that fits into one of the standard categories used by many health organizations:
- Underweight: BMI under 18.5
- Normal weight: BMI 18.5 – 24.9
- Overweight: BMI 25 – 29.9
- Obesity: BMI 30 or higher
A higher BMI can be associated with a higher risk of conditions such as type 2 diabetes, high blood pressure, heart disease and certain cancers. However, BMI does not directly measure body fat and does not consider where fat is stored.
For a more complete picture of your health, your healthcare provider may also look at your waist circumference, blood pressure, blood tests, family history and lifestyle.
BMI Calculator – Frequently Asked Questions
What is Body Mass Index (BMI)?
BMI is a simple number based on your weight and height. It is used as a quick screening tool to classify underweight, healthy weight, overweight or obesity in adults.
Is BMI an accurate measure of health?
BMI does not measure body fat directly and may not fully reflect health for everyone, especially athletes, very muscular people or older adults. It is one piece of information, not a diagnosis.
Can I use this BMI calculator if I am pregnant?
No. Standard BMI categories do not apply during pregnancy. If you are pregnant or breastfeeding, talk to your healthcare provider about healthy weight gain and nutrition.
What BMI is considered healthy for adults?
For most adults, a BMI between 18.5 and 24.9 is considered within the healthy weight range. However, your ideal range may be different based on your medical history and risk factors.
Should I talk to a doctor about my BMI?
Yes, especially if your BMI is in the underweight, overweight or obesity range, or if you have other risk factors such as high blood pressure, high cholesterol or diabetes in your family.
