Check your BMI quickly and understand what the number means in context.
A BMI calculator helps turn height and weight into a quick reference that is easier to read than raw measurements alone. It is commonly used to check whether a weight falls into a lower, typical, or higher range for a given height, and it is especially useful when comparing health guidance, fitness goals, checkup notes, or routine personal tracking.
Measurement system
Use metric units or switch to US units for feet, inches, and pounds.
Ages 20 and above are usually read with the adult BMI table.
Enter your height in centimeters.
Enter your weight in kilograms.
BMI
23.5
BMI Prime
0.9
Adult range
56.65625 kg to 76.25625 kg
BMI chart
A quick visual reference of the adult BMI scale with your current result highlighted.
Current result
BMI 23.5
Normal
Healthy weight range
56.65625 kg to 76.25625 kg
Reading note
Male adult reading shown with the standard WHO BMI table used for general reference.
Height changes the meaning of weight
Weight alone says very little without height. BMI connects both measurements so a person can understand whether the number falls into a lower, typical, or higher range for their height.
BMI works best as a reference, not a diagnosis
BMI is useful because it is simple and widely recognized, but it does not directly measure muscle, body fat distribution, bone density, or training level. Athletes, older adults, and very muscular people can have BMIs that need extra interpretation.
Age matters when the person is still growing
Adult BMI tables are commonly used from age 20 onward. For children and teens, clinicians usually rely on BMI-for-age percentiles, because growth patterns change with age and differ between boys and girls.
| Classification | BMI |
|---|---|
| Severe Thinness | 0 - 16 |
| Moderate Thinness | 16 - 17 |
| Mild Thinness | 17 - 18.5 |
| Normal | 18.5 - 25 |
| Overweight | 25 - 30 |
| Obese Class I | 30 - 35 |
| Obese Class II | 35 - 40 |
| Obese Class III | >= 40 |