BMI Calculator
Calculate your Body Mass Index (BMI) from height and weight inputs with standard category classification.
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This Body Mass Index (BMI) calculator estimates your body mass category based on your weight and height inputs. Select between metric measurements (kilograms and centimeters) and imperial measurements (pounds and inches) to match your preferred units. The tool applies standard calculation methods to compute your numerical BMI score and automatically rounds the output to one decimal place. Alongside your calculated score, the tool assigns a standard category: Underweight for values below 18.5, Normal weight for values from 18.5 to 24.9, Overweight for values from 25 to 29.9, and Obese for values of 30 or higher. You can evaluate different body measurements quickly to understand where specific numbers fall across standard ranges. To receive a valid calculation, ensure both height and weight are entered as positive numbers. If a zero or negative value is provided, the calculator returns an error notice highlighting the invalid input.
Instructions
- Select your measurement system: Metric (kilograms and centimeters) or Imperial (pounds and inches).
- Enter your weight into the designated input field.
- Enter your height into the height field, using centimeters for metric or inches for imperial.
- Click the calculate button to process your numbers.
- Review your rounded numerical BMI and the corresponding body mass classification in the result section.
Examples
- Metric input: A weight of 70 kg and a height of 175 cm with Metric selected produces a BMI score of 22.9 and a category of Normal.
- Imperial input: A weight of 160 lbs and a height of 68 inches with Imperial selected produces a BMI score of 24.3 and a category of Normal.
- Category evaluation: A weight of 95 kg and a height of 175 cm with Metric selected returns a BMI score of 31.0 and a category of Obese.
FAQ
What units should I use for height and weight?
When using the Metric setting, enter weight in kilograms and height in centimeters. When using the Imperial setting, enter weight in pounds and height in total inches.
How are the BMI categories defined?
The calculator categorizes a BMI below 18.5 as Underweight, 18.5 to 24.9 as Normal, 25 to 29.9 as Overweight, and 30 or greater as Obese.
How is the resulting BMI score rounded?
The calculated BMI score is automatically rounded to one decimal place before being presented in the result panel.
What happens if I enter zero or a negative number?
Both height and weight require positive numerical inputs. Entering zero or a negative value will return an error response indicating that valid positive inputs are required.