Health Tool
Free BMI Calculator Online
Calculate body mass index from height and weight using metric or imperial units. The calculation runs in your browser and updates instantly as you type.
BMI Calculator
Calculate body mass index with metric or imperial measurements.
Result
22.9
Healthy weight
Within the general adult reference range.
Healthy range, kg
56.7 - 76.3
BMI formula
kg / m2
Guide
How to use the BMI calculator
Use this BMI calculator to estimate body mass index from height and weight in either metric or imperial units. It is useful for a quick adult BMI screening number, but it should not replace medical advice or a full health assessment.
- 1
Choose your units
Select metric for centimeters and kilograms, or imperial for feet, inches, and pounds.
- 2
Enter height and weight
Type your height and weight into the calculator. The BMI result updates instantly as values change.
- 3
Review the BMI category
Check the calculated BMI number and its general adult category, such as healthy weight, overweight, or obesity range.
- 4
Copy or compare the result
Copy the BMI result or compare it with the displayed general reference range for adult BMI.
BMI calculation notes and limitations
- BMI is a screening estimate and does not directly measure body fat.
- Very muscular people may have a high BMI without the same health meaning.
- BMI categories for children and teens use age- and sex-specific percentiles.
- Pregnancy, medical conditions, and body composition can affect how BMI should be interpreted.
- Height and weight unit mistakes can create a very different BMI result.
Frequently asked questions
What is BMI?
BMI, or body mass index, is a simple ratio of weight to height that is commonly used as a general adult weight screening number.
What formula does this BMI calculator use?
The metric BMI formula is weight in kilograms divided by height in meters squared. Imperial inputs are converted to metric before calculating the result.
Is BMI a medical diagnosis?
No. BMI is a general screening tool and not a diagnosis. It does not directly measure body fat, muscle mass, or individual health risk.
Does this calculator store my height or weight?
No. The BMI calculation runs locally in your browser, so the values you enter stay on your device.