BMI Calculator
Switch between imperial and metric units, enter your height and weight, and get a quick BMI category instantly.
BMI Calculator
Check your Body Mass Index quickly
Note: 5'8" is 68 inches, 6'0" is 72 inches.
How to use this free BMI calculator
This BMI calculator is designed for quick health screening. Enter your weight and height, choose imperial or metric units, and the tool returns your body mass index with a category label. BMI is widely used because it gives a fast estimate of whether body weight falls into a lower, healthy, higher, or obesity range.
If you are targeting searches like bmi calculator kg and cm or bmi calculator with pounds and inches, this page supports both. The metric version uses kilograms and centimeters, while the imperial version uses pounds and inches. That makes the tool useful for students, fitness users, and everyday health checks.
What is BMI?
BMI stands for Body Mass Index. It is a number calculated from your height and weight. The formula does not measure body fat directly, but it gives a practical estimate that helps many people understand whether their weight is within a common healthy range. Doctors, fitness coaches, and health sites often use BMI as a starting point rather than a final diagnosis.
BMI formula
- Metric formula: weight in kilograms divided by height in meters squared.
- Imperial formula: 703 multiplied by weight in pounds divided by height in inches squared.
BMI categories
- Below 18.5: Underweight
- 18.5 to 24.9: Healthy
- 25 to 29.9: Overweight
- 30 and above: Obese
Example calculation
If someone weighs 70 kg and is 170 cm tall, the BMI is about 24.2. That falls into the healthy range. In imperial units, if someone weighs 154 pounds and is 67 inches tall, the result is almost the same. This helps users compare measurements across different systems without needing a manual formula sheet.