A BMI Calculator (Body Mass Index Calculator) is a health assessment tool that estimates whether a person's weight is in a healthy range relative to their height. Users input their height (in centimeters/meters or feet/inches) and weight (in kilograms or pounds), and the calculator computes their BMI value. This numerical result is then categorized into standard weight status ranges such as Underweight, Normal weight, Overweight, or Obese. Some advanced versions may also provide ideal weight ranges, body fat estimates, or health risk assessments based on BMI. This tool is widely used by healthcare professionals and individuals for basic weight-related health screening.