BMI Calculator
Calculate your Body Mass Index (BMI) instantly. Supports imperial and metric units. Free, private, no sign-up.
What is BMI Calculator?
BMI (Body Mass Index) is a simple measure that uses your height and weight to estimate whether you're at a healthy weight. It's widely used by healthcare professionals as a quick screening tool for weight categories that may lead to health problems.
Our free BMI calculator supports both imperial (lbs/ft) and metric (kg/cm) units. Simply enter your measurements to instantly see your BMI and which category you fall into: underweight, normal, overweight, or obese.
While BMI is a useful general indicator, it doesn't account for muscle mass, bone density, age, or body composition. Athletes may have a high BMI due to muscle weight. Always consult a healthcare provider for a complete health assessment.
How to Use This Tool
- Select your unit system — Imperial (lbs, ft/in) or Metric (kg, cm).
- Enter your weight — In pounds or kilograms.
- Enter your height — In feet/inches or centimeters.
- Read your BMI — Your score and category appear instantly.
Formula
Metric: BMI = weight (kg) / height (m)²
Imperial: BMI = (weight (lbs) / height (in)²) × 703
Example: 70 kg, 175 cm → BMI = 70 / (1.75)² = 22.9 (Normal weight)