BMI Calculator
The BMI Calculator determines your Body Mass Index (BMI), a measure of body fat based on height and weight. BMI is widely used by health professionals to screen for weight categories: underweight, normal, overweight, or obese. Enter your height and weight to instantly calculate your BMI and see which category you fall into. While BMI is not a direct measure of body fat, it is a useful screening tool for identifying potential weight-related health issues. For athletes and very muscular individuals, BMI may overestimate body fat.
Formula
BMI = weight (kg) / height (m)^2 Or in imperial units: BMI = 703 x weight (lbs) / height (in)^2 Categories: - Underweight: BMI < 18.5 - Normal: 18.5 - 24.9 - Overweight: 25 - 29.9 - Obese: BMI >= 30
Example
Weight: 70 kg, Height: 1.75 m BMI = 70 / (1.75)^2 BMI = 70 / 3.0625 BMI = 22.9 Category: Normal weight
How to Use
- Enter your weight (kg or lbs)
- Enter your height (cm or feet/inches)
- The calculator computes your BMI instantly
- Review your BMI category
- Consult a healthcare professional for personalized advice
Frequently Asked Questions
What is a healthy BMI?
A BMI between 18.5 and 24.9 is considered healthy for most adults. This range is associated with the lowest risk of weight-related health problems. However, BMI is just one measure and should be considered alongside other factors like waist circumference, diet, and physical activity.
Is BMI accurate for athletes?
BMI may overestimate body fat for athletes and very muscular individuals because muscle weighs more than fat. A bodybuilder with low body fat may have a high BMI. For athletes, body fat percentage is a more accurate measure.
Does BMI differ for men and women?
The BMI formula is the same for men and women. However, women naturally have more body fat than men at the same BMI. BMI also does not account for age-related changes in body composition.
What BMI is considered obese?
A BMI of 30 or above is classified as obese. Obesity is further categorized: Class I (30-34.9), Class II (35-39.9), and Class III (40+). Higher BMI categories are associated with increased health risks.
Should I use BMI or waist circumference?
Both are useful. BMI measures overall body size, while waist circumference measures abdominal fat. A waist circumference over 40 inches (men) or 35 inches (women) indicates increased health risk, regardless of BMI. Use both for a more complete picture.