BMI Calculator

Calculate Body Mass Index in imperial or metric units, view BMI categories and healthy weight ranges.

What is a BMI Calculator?

Calculate Body Mass Index (BMI) from height and weight. Supports imperial and metric units, with BMI category classification.

BMI is a screening tool used to assess whether a person's weight is within a healthy range for their height.

How to Calculate BMI

Follow these steps:

  • Choose your preferred unit system (imperial or metric).
  • Enter your height and weight.
  • Click Calculate to view your BMI and category.

Tips

  • BMI is a screening tool, not a diagnostic measure.
  • Consult a healthcare professional for a full health assessment.
  • Combine BMI with other health indicators for a complete picture.

Frequently Asked Questions

What is BMI?+
Body Mass Index (BMI) is a measure of body fat based on height and weight. It's calculated as weight in kilograms divided by height in meters squared. BMI is a screening tool, not a diagnostic measure of body fat or health.
What are the BMI categories?+
Underweight: below 18.5. Normal weight: 18.5-24.9. Overweight: 25.0-29.9. Obese: 30.0 and above. These categories are based on World Health Organization (WHO) guidelines for adults.
Is BMI accurate?+
BMI has limitations. It can't distinguish between muscle and fat mass, so muscular people may have a "high" BMI without having high body fat. It also doesn't account for age, sex, bone density, or fat distribution. Use it as one reference point, not a complete health picture.
Does BMI apply to children?+
For children, BMI uses age- and sex-specific percentiles rather than fixed adult categories. Pediatric BMI calculators account for normal growth patterns. This calculator is designed for adults (20+).

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BMI Calculator — free online bmi calculator, body mass index, bmi chart, healthy weight, weight calculator. No signup required. Works in your browser.