BMI Calculator

Calculate your Body Mass Index (BMI) instantly. Understand your weight status and get personalized health insights.

BMI Calculator

Enter your height and weight to calculate your BMI instantly. BMI is a simple index of weight-for-height commonly used to classify underweight, normal weight, overweight, and obesity.

Calculate Your BMI

Enter your height in centimeters, feet, or inches
Enter your weight in kilograms or pounds

BMI Categories Chart

BMI is categorized into four main groups according to World Health Organization (WHO) standards:

Underweight: BMI less than 18.5
Normal weight: BMI 18.5 to 24.9
Overweight: BMI 25 to 29.9
Obese: BMI 30 or greater
Note: These BMI categories are for adults (20 years and older). For children and teenagers, BMI is interpreted relative to age and sex.

How to Use the BMI Calculator

Follow these simple steps to calculate and interpret your BMI:

Step 1: Enter Measurements

Input your height and weight using your preferred units. The calculator automatically converts between units:

  • Height: Centimeters, feet, or inches
  • Weight: Kilograms or pounds
Step 2: Calculate BMI

Click the "Calculate BMI" button. Your BMI will be calculated using the formula:

BMI = Weight (kg) / [Height (m)]²

For imperial units, the calculator first converts to metric before calculation.

Step 3: Interpret Results

Check which BMI category you fall into:

  • Underweight - May indicate nutritional deficiency
  • Normal - Healthy weight range
  • Overweight - Increased health risks
  • Obese - Significant health risks
Step 4: Take Action

Based on your BMI category:

  • Consult healthcare provider for personalized advice
  • Consider lifestyle changes if needed
  • Monitor changes over time
  • Remember BMI is just one health indicator

BMI Calculation Examples

Here are some examples of BMI calculations for different height and weight combinations:

Height Weight BMI Category Interpretation
170 cm (5'7") 60 kg (132 lbs) 20.8 Normal Healthy weight range
165 cm (5'5") 50 kg (110 lbs) 18.4 Underweight Slightly below healthy range
180 cm (5'11") 85 kg (187 lbs) 26.2 Overweight Above healthy weight range
160 cm (5'3") 80 kg (176 lbs) 31.3 Obese Significantly above healthy range
175 cm (5'9") 70 kg (154 lbs) 22.9 Normal Ideal weight for height
Did You Know? BMI doesn't distinguish between muscle mass and fat mass. Athletes with high muscle mass may have a high BMI but low body fat.

Understanding BMI and Your Health

Health Risks of High BMI
  • Increased risk of heart disease
  • Higher chance of type 2 diabetes
  • Elevated blood pressure
  • Joint problems and osteoarthritis
  • Sleep apnea and breathing problems
  • Certain types of cancer
Health Risks of Low BMI
  • Nutritional deficiencies
  • Weakened immune system
  • Osteoporosis risk
  • Fertility issues
  • Fatigue and low energy levels
  • Hair loss and skin problems
Important: BMI is a screening tool, not a diagnostic tool. Always consult with a healthcare provider for a comprehensive health assessment. Other factors like waist circumference, muscle mass, age, gender, and ethnicity should also be considered.

Tips for Maintaining a Healthy BMI

Balanced Diet

Eat a variety of fruits, vegetables, whole grains, lean proteins, and healthy fats. Control portion sizes and limit processed foods.

Regular Exercise

Aim for at least 150 minutes of moderate aerobic activity or 75 minutes of vigorous activity weekly, plus strength training twice a week.

Quality Sleep

Get 7-9 hours of quality sleep nightly. Poor sleep affects hormones that regulate appetite and can lead to weight gain.