📖 Official User Guide
BMI Calculator — Check Your Body Mass Index & WHO Category Instantly — Step-by-Step Guide
Everything you need to know about calculating and interpreting your Body Mass Index (BMI) for better health tracking.
What is BMI?
BMI (Body Mass Index) was developed in the 1830s as a quick way to estimate whether a person has a healthy body weight for their height. It is widely used by healthcare professionals as a screening tool to identify potential weight-related health issues.
The Formula
- Metric: BMI = weight(kg) / height(m)²
- Imperial: BMI = (weight(lbs) / height(in)²) × 703
How to Use the BMI Calculator
- Choose your units: Select "Metric" (kg/cm) or "Imperial" (lbs/ft/in).
- Enter your height: Be as accurate as possible for the best results.
- Enter your weight: Use your current weight.
- Select your gender: This helps in calculating "Ideal Body Weight" using common formulas like Hamwi.
- Review results: Your BMI score, category, and healthy weight range will appear instantly.
Interpreting Your Results
The standard BMI categories are:
- Underweight: BMI less than 18.5
- Normal weight: BMI 18.5 to 24.9
- Overweight: BMI 25 to 29.9
- Obesity: BMI 30 or greater
Frequently Asked Questions
What is a healthy BMI for Indians?
While the global standard is 18.5–24.9, research suggests South Asians face higher metabolic risk at lower BMIs. An adjusted healthy range for Indians is often considered 18–22.9.
Is BMI accurate?
BMI is a screening tool, not a diagnostic one. It doesn't account for muscle mass, bone density, or body fat distribution. For example, athletes may have a "high" BMI due to muscle, not fat.
Is this BMI calculator free?
Yes, 100% free with no signup required. All calculations happen privately in your browser.