Free BMI Calculator
Check your Body Mass Index (BMI) from your height and weight. Free, and it runs in your browser.
Your BMI
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Ideal weight for your height: -
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| BMI | Category |
|---|---|
| < 18.5 | Underweight |
| 18.5 - 24.9 | Normal Weight |
| 25 - 29.9 | Overweight |
| ≥ 30 | Obese |
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What Is BMI?
Body Mass Index (BMI) is a number worked out from your weight and height. It is a simple screening tool that helps show whether your weight may be low, healthy or high for your height. BMI is not a diagnosis, and it does not measure body fat directly. Use the result as a starting point and talk to a doctor about your health.
BMI Formula
Metric: BMI = weight (kg) ÷ height (m)²
Imperial: BMI = 703 × weight (lb) ÷ height (in)²
How to Use the BMI Calculator
- Choose Metric (kg, cm) or Imperial (lb, ft, in).
- Enter your height and weight.
- Click Calculate BMI to see your BMI, your category and your ideal weight range.
The ideal weight range is the weight that would give a BMI between 18.5 and 24.9 at your height. This calculator is for adults aged 18 and above.
BMI Categories for Adults
| Category | WHO standard | Asia-Pacific and many Indian guidelines |
|---|---|---|
| Underweight | Below 18.5 | Below 18.5 |
| Normal weight | 18.5 to 24.9 | 18.5 to 22.9 |
| Overweight | 25 to 29.9 | 23 to 24.9 |
| Obesity | 30 and above | 25 and above |
This calculator shows the WHO standard categories. Many guidelines for Asian populations use lower cut-offs, because health risks can rise at a lower BMI. Ask your doctor which range is right for you.
BMI Examples
| Height and weight | BMI | WHO category |
|---|---|---|
| 175 cm, 50 kg | 16.3 | Underweight |
| 175 cm, 70 kg | 22.9 | Normal weight |
| 5 ft 10 in, 154 lb | 22.1 | Normal weight |
| 170 cm, 85 kg | 29.4 | Overweight |
| 175 cm, 95 kg | 31.0 | Obesity |
Ideal weight range example: at 175 cm, a BMI of 18.5 to 24.9 means a weight of about 56.7 kg to 76.3 kg.
What BMI Does Not Tell You
- It does not separate muscle from fat. A muscular person can have a high BMI and still be healthy.
- It does not show where fat is stored. Fat around the waist carries more health risk.
- It can be less reliable for older adults, pregnant women and children.
- For children and teenagers, doctors use BMI percentiles for age, not these adult categories.
Frequently Asked Questions
1. How accurate is BMI?
BMI is a good screening tool, but it does not measure body fat directly. Muscular people may have a high BMI, and some people with a normal BMI may still carry extra fat. Use it with other measures and a doctor's advice.
2. What is a healthy BMI?
According to the WHO, a BMI of 18.5 to 24.9 is the normal range for adults. Many guidelines for Asian populations use a lower upper limit of 22.9.
3. Is BMI different for men and women?
The formula and categories are the same for adult men and women. Body composition differs between them, so the same BMI can mean different body fat levels.
4. Can I use this BMI calculator for children?
No. This calculator is for adults aged 18 and above. For children, doctors use BMI percentiles for their age and sex.
5. How is the ideal weight calculated?
It is the range of weights that gives a BMI between 18.5 and 24.9 at your height.
6. Is my data saved?
No. The calculation runs in your browser and your height and weight are not sent to our server.
Frequently Asked Questions
Is this BMI accurate?
BMI uses WHO formula. It is a good screening tool but does not measure body fat directly. Athletes may have higher BMI due to muscle.
Is my data saved?
No. This calculator runs 100% in your browser. No health data is sent to any server.
What is ideal BMI?
Healthy BMI is 18.5 to 24.9. We also show ideal weight range for your height.
What is BMI for age?
This adult BMI is for 18+ years. For children, BMI percentile is used. Consult doctor for kids.