Free BMI Calculator
Find your body mass index in seconds. Enter your weight and height, choose metric or imperial units and see your BMI and weight category right away.
How to use the Free BMI Calculator
Choose your units, type in your weight and height and press Calculate BMI. Under 18.5 is underweight, 18.5 to 24.9 is normal weight, 25 to 29.9 is overweight and 30 or above is obese. These ranges are for adults.
What your BMI tells you
BMI compares your weight to your height and is a quick way to see whether your weight falls in a typical range. It does not measure body fat, muscle or bone, so athletes and older adults may get a result that does not match their health.
Treat it as a starting point and speak with a doctor for personal advice.
Frequently asked questions
How is BMI calculated?
BMI equals your weight in kilograms divided by your height in meters squared. With pounds and inches, the result is multiplied by 703.
What is a healthy BMI range?
For adults, 18.5 to 24.9 is generally considered the normal range.
Is the BMI calculator accurate for muscular people?
Not always. BMI does not separate muscle from fat, so very muscular people can show a high BMI while being healthy.
Can children use this BMI calculator?
No. This tool uses adult ranges. Children and teens are measured against growth charts for their age, so ask a doctor.
More free tools: BMR Calculator, Age Counter, Loan Calculator and Currency Converter.