BMI Calculator

Calculate your Body Mass Index, weight category, healthy weight range, and body health indicators instantly.

Personal Information
Years
ft
lb
Health Information
Healthy BMI Range
A BMI between 18.5 and 24.9 is considered healthy for most adults.
Result
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--

BMI = -- kg/m²

  • Healthy BMI range: 18.5 kg/m² – 25 kg/m²
  • Healthy weight for height: --
  • BMI Prime: --
  • Ponderal Index: -- kg/m³
BMI Table for Adults

This is the World Health Organization's (WHO) recommended body weight based on BMI values for adults. It is used for both men and women, age 20 or older.

Classification BMI Range – kg/m²
Severe Thinness< 16
Moderate Thinness16 – 17
Mild Thinness17 – 18.5
Normal18.5 – 25
Overweight25 – 30
Obese Class I30 – 35
Obese Class II35 – 40
Obese Class III> 40
BMI Chart for Adults

A graph of BMI categories based on World Health Organization data. Colors represent the major BMI categories; contour lines show integer BMI values for different height–weight combinations.

■ Underweight ■ Normal weight ■ Overweight ■ Moderately obese ■ Severely obese ■ Very severely obese
BMI Table for Children & Teens, Age 2–20

The Centers for Disease Control and Prevention (CDC) recommends BMI categorization for children and teens between age 2 and 20.

Category Percentile Range
Underweight<5%
Healthy Weight5% – 85%
At Risk of Overweight85% – 95%
Overweight>95%
BMI Visualization
YOUR BMI
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--
Healthy Weight Range --
Target Weight --
Weight Difference --
BMR
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Daily Calories
--
BMI Prime
--
Ponderal Index
--
Weight Status
--
Ideal BMI
22

Understanding Body Mass Index (BMI)

Learn how BMI works, why maintaining a healthy weight matters, and how to use BMI alongside other health indicators.

What Is Body Mass Index?

Body Mass Index (BMI) is a widely used screening measurement that estimates whether a person's weight is appropriate for their height. It is calculated by dividing body weight by height squared and provides a quick way to classify weight status.

Healthcare organizations around the world use BMI categories to identify potential health risks associated with underweight, overweight, and obesity.

While BMI does not directly measure body fat percentage, it remains one of the most practical tools for population-level and individual health assessments.

Why Maintaining a Healthy BMI Matters

Maintaining a healthy BMI is associated with improved cardiovascular health, better metabolic function, increased mobility, and reduced risk of chronic disease.

Excess body weight may contribute to conditions such as hypertension, type 2 diabetes, sleep apnea, joint problems, and heart disease.

Conversely, being significantly underweight may increase the risk of nutrient deficiencies, weakened immunity, reduced muscle mass, and osteoporosis.

How BMI Is Calculated

BMI uses a simple mathematical formula based on height and weight. For metric units, BMI equals weight in kilograms divided by height in meters squared.

This calculator automatically converts measurements, evaluates your BMI category, and provides additional metrics including BMI Prime, Ponderal Index, healthy weight range, and calorie requirements.

These supporting measurements help provide a broader picture of overall body composition and health status.

WHO BMI Classification Guide

Classification BMI Range General Health Assessment
Underweight Below 18.5 May indicate nutritional deficiencies or low body mass.
Normal Weight 18.5 – 24.9 Associated with lower health risk for most adults.
Overweight 25 – 29.9 Increased risk of future health complications.
Obesity Class I 30 – 34.9 Elevated risk of chronic disease.
Obesity Class II 35 – 39.9 Significantly increased health risks.
Obesity Class III 40+ Highest obesity-related health risk category.

Healthy Weight Management Tips

  • Focus on sustainable eating habits instead of short-term diets.
  • Combine cardiovascular exercise with strength training.
  • Monitor calorie intake and activity levels consistently.
  • Prioritize adequate sleep and stress management.
  • Track progress using multiple indicators, not BMI alone.
  • Consult healthcare professionals for personalized guidance.

Frequently Asked Questions

For most adults, a BMI between 18.5 and 24.9 is considered within the healthy weight range.

BMI is a useful screening tool but does not directly measure body fat percentage or body composition.

BMI Prime compares your BMI against the upper limit of the healthy BMI range (25), helping assess weight status more precisely.

Yes. Athletes with high muscle mass may have elevated BMI values despite having healthy body fat levels.

Calc Online Hub Medical Disclaimer

This BMI Calculator is provided for educational and informational purposes only. BMI is a screening tool and should not be used as the sole indicator of health, body composition, or disease risk. Factors such as muscle mass, age, sex, genetics, and medical conditions may influence the interpretation of BMI results. Always consult a qualified healthcare professional for personalized medical advice, diagnosis, or treatment recommendations.

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