A BMI Calculator (Body Mass Index Calculator) is a simple tool used to estimate whether a person’s weight is appropriate for their height. It calculates a numerical value based on your height and weight, which helps classify your body condition as underweight, normal weight, overweight, or obese according to standard health guidelines.
The BMI formula is:
BMI = weight (kg) / height² (m²)
Or in imperial units:
BMI = (weight (lbs) / height² (in²)) × 703
By entering your height and weight into a BMI calculator, the tool instantly computes your BMI score and places you into one of the categories defined by the World Health Organization (WHO).
BMI Categories:
Underweight: BMI less than 18.5
Normal weight: BMI between 18.5 and 24.9
Overweight: BMI between 25 and 29.9
Obese: BMI 30 or above
Why Use a BMI Calculator?
✅ Quick health assessment
✅ Track weight goals
✅ Used by doctors and fitness professionals
✅ Free and easy to use online
Limitations:
While BMI is a useful general indicator, it doesn’t account for muscle mass, age, gender, or body composition. Athletes, for example, may have a high BMI but low body fat.