
BMI Calculator
Your BMI is:
Health Advice
BMI Weight Ranges
BMI Calculator | Body Mass Index
- What is BMI?
- BMI Chart

What is a BMI Calculator?
Why Use a BMI Calculator?
How to Calculate BMI?
- Gather your measurements
- Use the BMI formula
- Example calculation
• BMI = 70 / (1.75 × 1.75)
• Result: BMI = 22.86
How to Use the BMI Calculator?
BMI Ranges
- Underweight
- Normal weight
- Overweight
- Obesity
- Severe obesity
BMI Table & Chart For Adults
Classification | BMI Range (kg/m²) |
---|---|
Severe Thinness | < 16 |
Moderate Thinness | 16 - 17 |
Mild Thinness | 17 - 18.5 |
Normal | 18.5 - 25 |
Overweight | 25 - 30 |
Obese Class I | 30 - 35 |
Obese Class II | 35 - 40 |
Obese Class III | > 40 |

BMI Table & Chart For Children and Teens
Category | Percentile Range |
---|---|
Underweight | < 5% |
Healthy weight | 5% - 85% |
At risk of overweight | 85% - 95% |
Overweight | > 95% |


Health Risks Related to Being Overweight
- Heart disease
- High blood pressure
- Stroke
- Type 2 diabetes
- Sleep apnea and breathing difficulties
- Joint pressure leading to osteoarthritis
- Cancers like breast, colon, and endometrial
- Fatty liver disease
- Gallbladder disease
- Hormonal imbalances impacting fertility and periods
- Kidney disease
- GERD (Gastroesophageal reflux disease)
- Breathing issues and reduced lung function
- Mental health problems such as anxiety and depression
- Skin issues like infections and rashes
Health Risks Related to Being Underweight
- Risk of malnutrition
- Weak immune system and frequent infections
- Osteoporosis and bone fractures due to low bone density
- Anemia and iron deficiency
- Fertility problems and irregular periods
- Fatigue and low energy levels
- Hair loss and brittle nails
- Muscle weakness and reduced muscle mass
- Vitamin deficiencies such as vitamin D and calcium
- Delayed wound healing
- Heart problems like low blood pressure and irregular heartbeat
- Risk of hypothermia due to low body fat
- Digestive issues like bloating and constipation
- Mental health problems such as anxiety and depression
- Complications during surgery or recovery
Tips for Maintaining Optimum Health
- Follow a balanced diet with nutrient-rich foods like fruits, vegetables, lean proteins, and healthy fats.
- Stay hydrated to keep your body functioning well.
- Include regular exercise in your routine, aiming for at least 150 minutes of moderate activity each week.
- Choose exercises you enjoy, such as walking or cycling, to stay consistent.
- Manage stress with practices like meditation or yoga for better emotional health.
- Get enough sleep to maintain energy and support cognitive function.
Limitations of BMI (Body Mass Index)
⦿ No distinction between muscle and fat: BMI doesn’t separate lean muscle from body fat, which can misclassify muscular individuals.
⦿ Ignores fat distribution: It doesn’t consider where fat is stored, missing health risks related to abdominal fat.
⦿ Not suitable for all populations: Its accuracy can vary for older adults, children, and different ethnic groups.
⦿ Excludes other health indicators: BMI doesn’t factor in important health aspects like blood pressure, cholesterol, or blood sugar.
⦿ No consideration for age and gender: It doesn’t adjust for natural differences in body composition based on age or gender.
What is the BMI formula?

What is the BMI prime formula?
Classification | BMI | BMI Prime |
---|---|---|
Severe Thinness | < 16 | < 0.64 |
Moderate Thinness | 16 - 17 | 0.64 - 0.68 |
Mild Thinness | 17 - 18.5 | 0.68 - 0.74 |
Normal | 18.5 - 25 | 0.74 - 1 |
Overweight | 25 - 30 | 1 - 1.2 |
Obese Class I | 30 - 35 | 1.2 - 1.4 |
Obese Class II | 35 - 40 | 1.4 - 1.6 |
Obese Class III | > 40 | > 1.6 |
What is Ponderal Index?

Frequently Asked Questions
BMI provides a general view of health, but it doesn’t account for muscle mass or fat distribution. It’s helpful as part of a wider health assessment.
A BMI of 25 means you’re classified as overweight, which may increase the risk of various health problems like heart disease and high blood pressure.
A BMI between 18.5 and 24.9 is considered healthy. This indicates that your weight is in a range that’s linked to better overall health and lower disease risks.
Yes, BMI is used for children, but it’s adjusted for age and gender. Percentiles help to determine if a child is underweight, normal weight, or overweight.
BMI helps assess if you're at a healthy weight for your height, which is crucial for reducing risks of chronic conditions like heart disease and diabetes.
BMI cannot determine your body fat percentage. It only provides a weight-to-height ratio and doesn’t account for muscle versus fat.
If you’re muscular, your BMI might place you in the overweight or obese category. This is because BMI doesn’t differentiate between muscle and fat.
While BMI can be used for older adults, it might not accurately reflect health due to muscle loss and fat gain with age. It’s important to use additional health measures.

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MS, MCh (G I cancer Surgeon)
Dr Harsh Shah is a well known GI & HPB Robotic Cancer Surgeon in ahmedabad. He treats cancers of esophagus, stomach, liver, pancreas, colon, rectum & small intestines. He is available at Apollo Hospital.