BMI Calculator

Check your Body Mass Index and understand your health status

For Men & Women Metric & Imperial Instant Analysis
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Enter your height and weight to see your BMI result.

About BMI

Body Mass Index (BMI) is a simple screening tool to estimate the amount of body fat. It works by dividing your weight in kilograms by the square of your height in meters.

Limitations

BMI is a useful general indicator but it does not differentiate between muscle and fat. Athletes may have a high BMI but low body fat. Always consult a doctor for a full assessment.

How to Calculate BMI Manually

Metric Formula
BMI = kg / m²
Weight (kg) ÷ Height (meters) squared
OR
Imperial Formula
BMI = 703 × (lb / in²)
703 × Weight (lbs) ÷ Height (inches) squared

Example: A person weighing 70kg and 1.75m tall.

70 ÷ (1.75 × 1.75) = 70 ÷ 3.0625 = 22.86 BMI

Comprehensive Guide to BMI

Body Mass Index (BMI) is a screening tool used to identify potential weight problems in adults. It is calculated by dividing a person's weight in kilograms by the square of their height in meters.

BMI Categories Breakdown
Category BMI Range (kg/m²) Health Risk
Underweight Less than 18.5 Malnutrition, Osteoporosis
Normal Weight 18.5 - 24.9 Low Risk
Overweight 25.0 - 29.9 Increased Risk
Obesity 30.0 or Higher High Risk
Risks of Being Overweight
  • Type 2 Diabetes and Insulin Resistance
  • High Blood Pressure (Hypertension)
  • Heart Disease and Stroke
  • Sleep Apnea and Breathing Problems
  • Joint Pain and Osteoarthritis
Risks of Being Underweight
  • Malnutrition and Vitamin Deficiencies
  • Weakened Immune System
  • Osteoporosis (Weak Bones)
  • Fertility Issues
  • Developmental Delays (in young people)

Frequently Asked Questions

Not always. Muscle is denser than fat. Athletes with high muscle mass may have a high BMI but low body fat. In these cases, body fat percentage is a better health indicator.

BMI is calculated differently for children and teens. It is compared against percentiles for children of the same age and sex. This calculator is primarily designed for adults (20+ years).

Yes, this BMI calculator is 100% free and we do not store any of your personal health data. All calculations are performed instantly in your browser.

If your BMI falls outside the "Normal" range, or if you have concerns about your weight, diet, or overall health, it is recommended to consult a healthcare professional.
Medical Disclaimer: This tool is for informational purposes only. It is not intended to provide medical advice, diagnosis, or treatment. Always seek the advice of your physician.