Body Mass Index (BMI) Calculator

Calculate your Body Mass Index (BMI) to assess your weight category. BMI is a measure of body fat based on height and weight for adults.

BMI Formula

The Body Mass Index is calculated using this formula:

\[\text{BMI} = \frac{\text{Weight (kg)}}{\text{Height (m)}^2}\]

BMI Categories:

  • Underweight: BMI less than 18.5
  • Normal weight: BMI 18.5-24.9
  • Overweight: BMI 25-29.9
  • Obese: BMI 30 or greater

BMI Calculator

Your BMI

0.0

kg/m²

Category

N/A

Unknown

Weight

0

kg

Height

0

cm

Status: Enter values

lbs
Feet and inches

BMI Scale

Underweight
<18.5
Normal
18.5-24.9
Overweight
25-29.9
Obese
≥30
0
Healthy Min (kg)
0
Healthy Max (kg)
0
To Healthy (kg)

Health Recommendations

Based on your BMI category, here are personalized health recommendations:

  • Maintain a balanced diet with fruits, vegetables, and lean proteins
  • Engage in regular physical activity (150 minutes per week)
  • Stay hydrated and get adequate sleep
  • Consider consulting with a healthcare professional

BMI Assessment & Recommendations

Based on your BMI of 0.0, you are classified as N/A.

  • Continue monitoring your weight and BMI regularly
  • Maintain a healthy lifestyle with balanced nutrition
  • Engage in regular physical activity
  • Consult healthcare professionals for personalized advice

BMI Knowledge Quiz

Question 1: BMI Formula

What is the formula for calculating BMI?

Solution

The correct answer is b) Weight(kg) / Height(m)². BMI is calculated by dividing weight in kilograms by the square of height in meters.

Key Concept

The BMI formula uses the squared height because body mass typically scales with the cube of linear dimensions, but height is a linear measurement.

Question 2: Normal BMI Range

What is the normal BMI range according to WHO standards?

Solution

The correct answer is b) 18.5-24.9. This is the standard range for normal weight classification.

Important Rule

These ranges apply to adults aged 20 and older. Children and teens have different standards.

Question 3: BMI Classification

What BMI category applies to a BMI of 32?

Solution

The correct answer is d) Obese. A BMI of 32 falls in the obese category (BMI ≥ 30).

Clinical Tip

BMIs above 30 are associated with increased health risks and may require medical intervention.

Question 4: BMI Limitations

Which of the following is a limitation of BMI?

Solution

The correct answer is d) All of the above. BMI has several limitations including not distinguishing muscle from fat, not accounting for bone density, and not considering age and sex.

Educational Note

BMI is a screening tool but not a diagnostic tool. Additional assessments may be needed for a complete health picture.

Question 5: Healthy BMI Maintenance

What is the most effective approach to maintain a healthy BMI?

Solution

The most effective approach is to maintain a balance between calorie intake and expenditure through a combination of healthy eating habits and regular physical activity. This includes consuming a balanced diet rich in fruits, vegetables, whole grains, and lean proteins while limiting processed foods and engaging in at least 150 minutes of moderate-intensity aerobic activity per week.

Common Mistake to Avoid

Don't rely solely on BMI as the only indicator of health. Consider other factors like waist circumference, body composition, and overall lifestyle.

Q&A

Q: I calculated my BMI as 28.5. What does this mean and what should I do?

A: A BMI of 28.5 falls in the "Overweight" category (25-29.9). This suggests a modest increase in health risks.

Recommended Actions:

  • Modest Weight Loss: Aim for 5-10% of current body weight
  • Dietary Changes: Reduce calorie intake by 500-750 calories/day
  • Exercise: 150 minutes of moderate activity weekly
  • Monitoring: Track progress monthly

Small changes can make a significant difference in health outcomes. Consider consulting a healthcare provider for personalized guidance.

Q: I'm an athlete with a BMI of 27. Am I really overweight?

A: BMI has limitations for athletes due to higher muscle mass. Muscle weighs more than fat.

Alternative Measures:

  • Body Composition: Measure body fat percentage
  • Waist Circumference: Assess abdominal fat
  • Performance Metrics: Focus on athletic performance
  • Other Indicators: Blood pressure, cholesterol, glucose

For athletes, BMI should be interpreted alongside other health markers rather than as a standalone indicator.

About BMI

Health Team
BMI is a screening tool for weight categories. This calculator provides estimates only and should not replace professional medical evaluation. Updated: April 2026.