Home
Back
BMI Formula:
| From: | To: |
Body Mass Index (BMI) is a simple calculation using a person's height and weight. The formula is BMI = kg/m² where kg is a person's weight in kilograms and m² is their height in meters squared. BMI provides a reliable indicator of body fatness for most people and is used to screen for weight categories that may lead to health problems.
The calculator uses the BMI formula:
For metric units:
For imperial units:
Details: BMI is a simple, inexpensive screening method for weight category—underweight, healthy weight, overweight, and obesity. While BMI doesn't measure body fat directly, research has shown that BMI correlates to more direct measures of body fat.
Tips: Select your preferred unit system (metric or imperial), enter your weight and height. For most accurate results, measure your height without shoes and weight in light clothing.
Q1: What is a healthy BMI range?
A: For adults 20 years and older, BMI is interpreted using standard weight status categories: Underweight (BMI < 18.5), Normal weight (BMI 18.5-24.9), Overweight (BMI 25-29.9), and Obese (BMI ≥30).
Q2: Are there limitations to BMI?
A: BMI may overestimate body fat in athletes and others with muscular builds and may underestimate body fat in older persons and others who have lost muscle mass.
Q3: Is BMI interpreted the same way for children as it is for adults?
A: No, BMI for children and teens is age- and sex-specific and is often referred to as BMI-for-age.
Q4: How often should I check my BMI?
A: For most adults, checking BMI once a year is sufficient unless you're actively trying to lose or gain weight.
Q5: Should athletes be concerned about their BMI?
A: Athletes with high muscle mass may have a high BMI but low body fat. Additional measurements like waist circumference may be more appropriate.