Check your Body Mass Index with our Free Online BMI Calculator. Find out if you are underweight, normal, overweight, or obese instantly.
Check your Body Mass Index with our Free Online BMI Calculator. Find out if you are underweight, normal, overweight, or obese instantly.
BMI is a screening tool for adults (18+). It may not apply to athletes, pregnant people, or those with high muscle mass.
Add your weight in kilograms (kg) or switch units if needed. This ensures accurate calculation of your body mass index.
Provide your height in feet and inches. The calculator combines this with your weight to measure your BMI.
Press the button and view your BMI result, showing whether you fall into underweight, normal, overweight, or obese range.
Modify the values and click Calculate BMI to get instant results. The calculator supports weight in kilograms and height in feet & inches, making it quick and easy to use for everyday health checks.
Our BMI Calculator instantly processes your weight (kg) and height (ft & in) to generate:
Your BMI value (kg/m²)
The corresponding weight category (underweight, normal, overweight, obese)
A quick reference to whether you fall into a healthy range
This saves you from using complex formulas or charts, making it ideal for students, professionals, and anyone wanting fast, accurate results.
According to the World Health Organization (WHO), BMI values are divided into the following ranges:
Severe Thinness: < 16
Moderate Thinness: 16 – 17
Mild Thinness: 17 – 18.5
Normal Range: 18.5 – 25
Overweight: 25 – 30
Obese Class I: 30 – 35
Obese Class II: 35 – 40
Obese Class III: > 40
These ranges apply to both men and women aged 20 and above.
For children and teenagers (ages 2–20), BMI is interpreted differently. Instead of fixed ranges, it is measured using percentiles:
Underweight: < 5%
Healthy Weight: 5% – 85%
At Risk of Overweight: 85% – 95%
Overweight: > 95%
This method takes age and gender into account, making it more accurate for younger people.
Age: 25
Height: 5 ft 10 in (178 cm)
Weight: 160 lbs (72.5 kg)
Result: BMI = 23 (Normal)
Healthy Range: 18.5 – 25 kg/m²
This means the person is within the healthy weight category, with a safe margin.
Having a BMI above 25 significantly increases health risks, such as:
High blood pressure and cholesterol problems
Type 2 diabetes
Heart disease and stroke
Osteoarthritis and sleep apnea
Increased cancer risks (colon, breast, kidney, liver, etc.)
Lower quality of life and higher mortality risks
Maintaining a healthy BMI through diet and exercise is vital for long-term health.
A BMI below 18.5 also poses health issues, including:
Malnutrition and vitamin deficiencies
Bone weakness (osteoporosis)
Reduced immune system function
Growth issues in children and teens
Reproductive health complications in women
Higher surgical risks and possible underlying health problems
Being underweight should be taken seriously, and medical consultation is recommended.
The Free BMI Calculator provides your body mass index in seconds. You don’t need to memorize formulas or do manual math. Just enter your weight and height, click calculate, and get your health category instantly with clear results.
Understanding your BMI helps you track weight and overall health. The Body Mass Index Calculator shows whether you are underweight, normal, overweight, or obese, giving you a starting point for fitness and nutrition planning.
Our Free Online BMI Calculator is completely free, requires no downloads, and works on any device. Whether on desktop, tablet, or mobile, you can check your BMI anytime, anywhere, with just one click.
A BMI Calculator is a tool that uses weight and height to calculate body mass index. It shows whether a person is underweight, normal, overweight, or obese. It’s widely used as a quick health check.
The calculator divides weight (kg) by height in meters squared. This formula provides your Body Mass Index, which is then matched against standard health ranges. Results are shown instantly online.
A normal BMI usually falls between 18.5 and 24.9. Below 18.5 is considered underweight, 25–29.9 overweight, and 30+ obese. This gives a general guide to weight health.
While BMI is a useful indicator, it doesn’t account for muscle mass, bone density, or body composition. Athletes and children may need more specific health checks beyond BMI alone.
Yes. The Free Online BMI Calculator works the same for both men and women. However, factors like age, fitness, and lifestyle should also be considered when interpreting results.
You can calculate BMI using kilograms (kg) or pounds (lbs) for weight, and feet/inches or centimeters for height. The tool converts values automatically for accurate results.
There’s no strict rule, but checking your BMI every few weeks or months can help you track weight trends, especially if you’re on a fitness plan or weight-loss program.
Yes. The BMI Calculator is mobile-friendly and works in your browser. You can check results instantly on your phone, making it convenient while traveling or at the gym.
If your BMI is above normal, it’s best to review your diet, increase physical activity, and consult a doctor for advice. BMI is a screening tool, not a diagnosis.
Yes. The Free BMI Calculator is completely free, unlimited, and requires no registration. You can check your Body Mass Index as many times as you want with no restrictions.
While BMI is a useful screening tool, it has limitations:
It does not directly measure body fat percentage
Muscle mass can affect results (athletes may appear “overweight” by BMI)
Does not account for fat distribution (belly fat is more harmful than overall fat)
Other measures like waist-to-hip ratio, waist circumference, and body fat percentage provide additional insights
Therefore, BMI should be seen as a starting point, not a final diagnosis. Always consult a healthcare professional for a full evaluation.
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Free Tool Mart provides free online calculators and tools for education and information only. Results are not professional financial, legal, or medical advice. Always verify with experts.
Free Tool Mart provides free online calculators and tools for educational and informational purposes. Results should be verified and are not intended as professional financial, legal, or medical advice. Always consult qualified professionals for important decisions.