How do I find my BMI score?
The fastest way to find your BMI score is to enter your height and weight into a BMI calculator. The calculator applies the correct formula, rounds the result, and places the score into an adult BMI category. You can also calculate it yourself if you know which unit system you are using.
Metric BMI formula
BMI = weightKg / (heightM * heightM)
US BMI formula
BMI = 703 * weightLb / (heightIn * heightIn)
Step-by-step BMI calculation
Step 1
Measure your height
Use centimetres for the metric formula, or feet and inches for the US formula. If you use feet and inches, convert the full height to inches before calculating.
Step 2
Measure your weight
Use kilograms for metric units or pounds for US units. A recent, consistent measurement gives the most useful estimate.
Step 3
Apply the BMI formula
Metric BMI is weight in kilograms divided by height in metres squared. US BMI is 703 times weight in pounds divided by height in inches squared.
Step 4
Compare the score with adult BMI categories
For most adults, 18.5 to 24.9 is the healthy BMI range, below 18.5 is underweight, 25 to 29.9 is overweight, and 30 or above is obesity.
Example BMI score
Suppose an adult weighs 70 kg and is 1.75 m tall. The metric calculation is 70 divided by 1.75 squared. That gives a BMI of about 22.9, which falls within the common adult healthy BMI range of 18.5 to 24.9.
If using US units, suppose an adult weighs 165 lb and is 69 inches tall. The calculation is 703 times 165, divided by 69 squared. That gives a BMI of about 24.4.
What your BMI score means
BMI is a screening number, not a diagnosis. A score below 18.5 is usually classified as underweight for adults. A score from 18.5 to 24.9 is usually considered the healthy BMI range. A score from 25 to 29.9 is classified as overweight, and 30 or higher is classified as obesity.
BMI does not measure body fat directly and does not account for muscle mass, pregnancy, age-related body composition changes, or individual medical history. If your result concerns you, speak with a qualified healthcare provider.
Medical disclaimer
This calculator is for general informational purposes only and does not replace professional medical advice. Always consult a qualified healthcare provider for personal health concerns.