BMI Calculator
Enter your weight and height to calculate your Body Mass Index and see your category.
What Is BMI?
Body Mass Index (BMI) is a simple screening measure that estimates whether your weight is in a healthy range for your height. It's calculated by dividing weight by the square of height, and it's widely used by health organizations as a quick, low-cost starting point for assessing weight-related health risk.
How BMI Is Calculated
In metric units, BMI = weight (kg) ÷ height (m)². In imperial units, BMI = 703 × weight (lb) ÷ height (in)². For example, a person weighing 70 kg who is 175 cm tall has a BMI of about 22.9.
BMI Categories
The standard adult BMI categories are: below 18.5 is considered underweight, 18.5 to 24.9 is considered normal weight, 25 to 29.9 is considered overweight, and 30 or above is considered obese.
Limitations of BMI
BMI does not directly measure body fat and doesn't account for muscle mass, bone density, age, or sex. A very muscular person, for example, may have a high BMI without having excess body fat. BMI is best used as a general starting point, not a diagnosis.
Frequently Asked Questions
Is BMI accurate for everyone?
BMI is a useful general screening tool, but it doesn't account for muscle mass or body composition, so it may be less accurate for athletes, older adults, or pregnant women.
What is a healthy BMI?
For most adults, a BMI between 18.5 and 24.9 is considered within the normal weight range.
Can I use pounds and feet instead of kilograms?
Yes, switch to the Imperial option to enter your weight in pounds and height in feet and inches.
Should I make health decisions based only on BMI?
No. BMI is a starting point for a conversation, not a full health assessment. Speak with a healthcare provider for personalized advice.
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