Your BMI
Enter your details
For personal medical advice, talk with a qualified health professional.
BMI Calculator – Free Body Mass Index Calculator & BMI Chart
Body Mass Index (BMI) Calculator
What Is BMI?
Body Mass Index (BMI) is a simple measurement used to estimate whether your body weight is appropriate for your height. It is calculated using your weight and height and helps identify whether you are underweight, at a healthy weight, overweight, or living with obesity.
Healthcare professionals commonly use BMI as a screening tool because it is quick, inexpensive, and easy to calculate. Although BMI does not directly measure body fat, it provides a useful starting point for assessing weight-related health risks in adults.
Use our free BMI Calculator above to instantly calculate your Body Mass Index using either metric (kilograms and centimeters) or imperial (pounds and feet/inches) units.
BMI Formula
The Body Mass Index formula is:
BMI = Weight (kg) ÷ Height² (m²)
Example
- Weight: 70 kg
- Height: 1.75 m
BMI = 70 ÷ (1.75 × 1.75)
BMI = 22.9
This result falls within the healthy weight range.
BMI Categories
| BMI Range | Weight Category |
|---|---|
| Below 18.5 | Underweight |
| 18.5–24.9 | Healthy Weight |
| 25.0–29.9 | Overweight |
| 30.0–34.9 | Obesity Class I |
| 35.0–39.9 | Obesity Class II |
| 40 or higher | Obesity Class III |
What Is a Healthy BMI?
For most adults aged 18 years and older, a BMI between 18.5 and 24.9 is generally considered a healthy weight range.
Maintaining a healthy BMI may help reduce the risk of:
- Heart disease
- High blood pressure
- Type 2 diabetes
- Stroke
- Sleep apnea
- Osteoarthritis
- Fatty liver disease
- Certain cancers
BMI is only one part of assessing overall health. Factors such as diet, physical activity, muscle mass, body composition, medical history, and waist circumference should also be considered.
BMI Chart
| Height | Healthy Weight Range |
|---|---|
| 150 cm | 42–56 kg |
| 155 cm | 44–60 kg |
| 160 cm | 47–64 kg |
| 165 cm | 50–68 kg |
| 170 cm | 54–72 kg |
| 175 cm | 57–76 kg |
| 180 cm | 60–81 kg |
| 185 cm | 63–85 kg |
| 190 cm | 67–90 kg |
How to Calculate BMI
Calculating BMI is easy.
Step 1
Measure your height accurately.
Step 2
Measure your body weight.
Step 3
Enter your height and weight into the calculator.
Step 4
Click Calculate BMI.
Within seconds, you’ll see:
- Your BMI score
- Your weight category
- Health interpretation
Why Is BMI Important?
BMI helps healthcare professionals identify people who may be at increased risk for diseases associated with excess or insufficient body weight.
A higher BMI may increase the likelihood of:
- High cholesterol
- Heart disease
- High blood pressure
- Type 2 diabetes
- Stroke
- Gallbladder disease
- Certain cancers
A very low BMI may be associated with:
- Nutritional deficiencies
- Weakened immune system
- Osteoporosis
- Muscle loss
- Fertility problems
Advantages of BMI
- Quick to calculate
- No laboratory tests required
- Suitable for population screening
- Used worldwide
- Recommended by many health organizations
- Free and easy to understand
Limitations of BMI
BMI is a screening tool, not a diagnostic test.
It does not distinguish between:
- Muscle and fat
- Bone density
- Body fat distribution
- Fitness level
For example, athletes may have a high BMI because of increased muscle mass rather than excess body fat.
BMI for Men and Women
The BMI calculation is the same for adult men and women.
However, body fat percentage naturally differs between sexes. Women generally have a higher percentage of body fat than men at the same BMI.
BMI for Older Adults
As people age, muscle mass often decreases while body fat increases.
BMI should therefore be interpreted alongside other health assessments, especially in older adults.
BMI During Pregnancy
BMI can be useful before pregnancy for assessing weight status, but it is not intended to evaluate weight gain during pregnancy. Pregnant individuals should follow pregnancy-specific guidance from their healthcare provider.
Tips for Maintaining a Healthy BMI
- Eat a balanced diet rich in vegetables, fruits, whole grains, lean proteins, and healthy fats.
- Stay physically active with regular aerobic exercise and strength training.
- Aim for adequate sleep and manage stress.
- Drink enough water throughout the day.
- Limit sugary drinks, ultra-processed foods, and excessive alcohol.
- Monitor your weight periodically rather than focusing on daily fluctuations.
Frequently Asked Questions
What does BMI stand for?
BMI stands for Body Mass Index.
Is BMI accurate?
BMI is a useful screening tool but does not directly measure body fat or overall health.
What is a healthy BMI?
For most adults, a BMI between 18.5 and 24.9 is generally considered healthy.
Can athletes have a high BMI?
Yes. Athletes often have greater muscle mass, which can increase BMI without indicating excess body fat.
Does BMI apply to children?
No. Children and adolescents are assessed using age- and sex-specific BMI percentiles rather than the standard adult BMI categories.
Can BMI diagnose obesity?
BMI alone cannot diagnose obesity. Healthcare professionals may also consider waist circumference, body composition, medical history, and other clinical assessments.
Conclusion
The Body Mass Index (BMI) Calculator is a fast and convenient way to estimate whether your weight is appropriate for your height. While BMI is widely used as an initial screening tool, it should be interpreted alongside other health information rather than used as the sole measure of health. Maintaining a balanced diet, staying physically active, getting enough sleep, and attending regular health check-ups all contribute to long-term well-being.