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Calculate body mass index using metric or imperial height and weight measurements.
A quick overview to help you understand what this tool does and how to use it well.
Use this BMI calculator to estimate your body mass index from height and weight. BMI, short for body mass index, is a common screening tool used to place adult body size into broad ranges such as underweight, healthy weight, overweight, and obesity.
This calculator supports both metric and imperial units, so you can enter centimeters and kilograms or feet, inches, and pounds. It is useful for getting a quick estimate, comparing changes over time, or understanding where a result falls within standard adult BMI ranges.
BMI is best treated as a starting point rather than a full health assessment. It can be helpful for general screening, but it does not directly measure body fat, muscle mass, or overall health status.
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Your result updates after a successful calculation.
BMI
24.6
Estimated body mass index based on the selected height and weight inputs.
BMI category
Healthy weight
General adult BMI category based on the calculated result.
Reference note
18.5 to 24.9 is generally considered a healthy BMI range for adults.
General adult BMI guidance commonly used for quick interpretation.
See the formula, calculation method, and reasoning behind the result.
BMI is calculated by dividing body weight by height squared. This creates a simple ratio that helps estimate whether weight is broadly low, typical, high, or very high relative to height.
Metric formula: BMI = weight in kilograms ÷ (height in meters × height in meters)
If you use imperial measurements, the calculator first converts feet, inches, and pounds into metric values and then applies the same formula.
General adult BMI categories are commonly interpreted as:
BMI is popular because it is fast and easy to calculate, but it has important limits. It does not distinguish between fat and muscle, and it does not capture the full picture of health. That means the result is most useful as a screening estimate, not as a complete diagnosis.
Estimate BMI for someone who is 178 centimeters tall and weighs 78 kilograms. Convert height to meters, square it, and divide the body weight by that number. The result shows how the person’s weight compares to common adult BMI reference ranges.
Example results
Common questions about this tool.
BMI stands for body mass index. It is a simple screening measurement that compares weight to height to estimate whether body size falls into a common adult reference range.
BMI is calculated by dividing body weight by height squared. In metric form, that means kilograms divided by meters squared. If you use imperial inputs, the calculator converts them first and then performs the same calculation behind the scenes.
Yes. This calculator supports both centimeters and kilograms as well as feet, inches, and pounds.
For most adults, a BMI from 18.5 to 24.9 is commonly considered a healthy range. Under 18.5 is often classified as underweight, 25 to 29.9 as overweight, and 30 or higher as obesity.
Not always. BMI is a broad screening tool and does not directly measure body fat, muscle mass, bone density, or health conditions. People with more muscle or other body composition differences may find BMI less representative.
No. BMI is useful as a quick screening estimate, but it should not replace professional medical advice or a more complete health evaluation.
BMI can be useful for tracking broad trends over time, especially when weight or lifestyle changes are happening. It is often more useful for comparison and screening than as a one-time verdict.