BMI Calculator (Body Mass Index)
Calculates your Body Mass Index (BMI) to determine if your weight is in a healthy range.
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BMI Calculator (Body Mass Index)
The BMI tool helps you determine your Body Mass Index (BMI) using your weight and height. Body Mass Index is a widely used measurement to evaluate whether a person has a healthy body weight for a given height.
This online BMI tool works for both metric (kg, meters) and imperial (pounds, inches) units.
What Is BMI?
Body Mass Index (BMI) is a numerical value derived from a person’s weight and height. It is commonly used to classify underweight, normal weight, overweight, and obesity in adults.
BMI provides a simple way to assess whether body weight is proportionate to height. It is used worldwide by healthcare professionals and organizations such as the World Health Organization (WHO).
BMI Formula
BMI is calculated by dividing body weight by the square of height.
Metric Formula (kg, meters)
weight (kg)
BMI = -----------------
height² (m²)
Where:
- weight is measured in kilograms (kg)
- height is measured in meters (m)
Imperial Formula (pounds, inches)
weight (lb) × 703
BMI = -----------------------
height² (in²)
Where:
- weight is measured in pounds (lb)
- height is measured in inches (in)
- 703 is the conversion factor used in the imperial formula
BMI Categories
The standard BMI classification for adults is:
| BMI Range | Classification |
|---|---|
| Below 18.5 | Underweight |
| 18.5 – 24.9 | Normal weight |
| 25.0 – 29.9 | Overweight |
| 30.0 and above | Obesity |
These categories are intended for adults aged 20 and older.
Why Is BMI Important?
Maintaining a healthy BMI may help reduce the risk of:
- Cardiovascular diseases
- Type 2 diabetes
- High blood pressure
- Metabolic syndrome
- Certain types of cancer
BMI is commonly used as a screening tool to identify potential weight-related health risks.
Limitations of BMI
Although BMI is useful for population-level analysis, it does not directly measure body fat.
BMI may be less accurate for:
- Athletes and muscular individuals
- Pregnant women
- Elderly people
- Children and teenagers
- Individuals with atypical body composition
For a more complete health assessment, BMI should be considered alongside other measurements such as waist circumference and body fat percentage.
live_help Frequently Asked Questions (FAQ)
Frequently Asked Questions
What is a healthy BMI?
For most adults, a BMI between 18.5 and 24.9 is considered healthy.
Is BMI accurate?
BMI is a screening tool, not a diagnostic tool. It provides a general estimate but does not measure body fat directly.
Is BMI different for men and women?
The BMI formula is the same for men and women, but body fat distribution may differ.
Should I use BMI if I lift weights?
Highly muscular individuals may have a higher BMI without having excess body fat. In such cases, BMI may overestimate health risk.
Is BMI used for children?
BMI for children and teenagers is age- and sex-specific and is interpreted using percentile charts rather than adult categories.