BMI Calculator
Calculate Body Mass Index from height and weight
What is BMI Calculator?
BMI Calculator is a free online tool that calculates your Body Mass Index from your height and weight. BMI is a widely used screening tool that categorizes weight status into underweight, normal weight, overweight, and obese ranges. Enter your height and weight in metric (cm/kg) or imperial (ft-in/lb) units, and the tool instantly calculates your BMI with a clear category indicator. It also shows where you fall on the BMI scale with a visual indicator. All calculations happen in your browser with no personal health data sent to any server. While BMI is a useful initial assessment, it does not account for muscle mass, bone density, age, or gender, so consult a healthcare professional for comprehensive health evaluation.
How to Use
- Enter your height (cm) and weight (kg).
- Your BMI value and category (Underweight/Normal/Overweight/Obese) are shown with color coding.
Tips & Best Practices
- BMI is a screening tool, not a diagnostic tool. Always consult a healthcare professional for medical advice.
- Switch between metric and imperial units depending on your preference.
- A BMI between 18.5 and 24.9 is generally considered normal weight for adults.
- Remember that BMI does not distinguish between muscle and fat mass.
- Track your BMI over time to monitor weight management progress.
Use Cases
Health Screening
Quickly assess weight status category as part of general health awareness.
Fitness Tracking
Monitor BMI changes over time alongside your fitness and nutrition programs.
Medical Forms
Calculate BMI values required on health questionnaires and insurance applications.
Education
Learn about BMI categories and their health implications for health education.
FAQ
How is BMI calculated?
BMI = weight(kg) / height(m)^2. For example: 70kg, 170cm gives 70 / (1.7)^2 = 24.2
What is a normal BMI range?
According to WHO, 18.5-24.9 is normal weight. Below 18.5 is underweight, 25+ is overweight, and 30+ is obese.
What is BMI (Body Mass Index)?
BMI divides weight (kg) by the square of height (m), and is an index recommended by WHO for indirectly measuring obesity levels.
Is my body information sent to any server?
No, all BMI calculations are performed locally in your browser and your height and weight data is not transmitted externally.
What are the limitations of BMI?
BMI does not account for muscle mass, body fat percentage, or bone structure, so athletes with high muscle mass may get misleadingly high readings.
Are children's BMI standards the same as adults'?
No, children and adolescents use BMI percentiles based on age and sex. The standards in this tool are designed for adults aged 18 and older.
What is BMI?
BMI (Body Mass Index) is calculated as weight (kg) divided by height (m) squared. It is a screening tool for weight categories.
Is my health data collected?
No, all calculations happen in your browser. No personal data is sent to any server.
What are the BMI categories?
Underweight: below 18.5, Normal: 18.5-24.9, Overweight: 25-29.9, Obese: 30 and above.
Is BMI accurate for everyone?
BMI does not account for muscle mass, age, gender, or body composition. Athletes with high muscle mass may have high BMI despite being healthy.
Does BMI apply to children?
Children's BMI is interpreted differently using age and sex-specific percentile charts. This tool is designed for adults.
What is a healthy BMI range?
A BMI between 18.5 and 24.9 is considered normal weight for most adults, but individual health factors vary.
Should I use metric or imperial units?
Use whichever you are more familiar with. The calculator produces the same BMI result regardless of the unit system.