BMI Calculator – Body Mass Index Calculation
Calculate your Body Mass Index (BMI) and assess your weight with our professional calculator
BMI Calculator
Calculate your Body Mass Index (BMI) and assess your weight
What is BMI?
The Body Mass Index (BMI) is a calculation method that measures the ratio of weight to height. It helps determine whether someone is underweight, normal weight, overweight, or obese.
BMI Formula
BMI = weight (kg) / height² (m)
BMI Categories
- Below 18.5: Underweight
- 18.5-24.9: Normal weight
- 25-29.9: Overweight
- 30-34.9: Obesity (Class I)
- 35-39.9: Obesity (Class II)
- Above 40: Severe obesity (Class III)
Important: BMI is only a guideline and does not take into account muscle mass, bone density, or other health factors. Always consult your doctor regarding questions about your weight.
What is BMI and why is it important?
The Body Mass Index (BMI) is a calculation method that measures the ratio of weight to height. This widely accepted indicator helps determine whether someone is underweight, normal weight, overweight, or obese.
BMI Formula and calculation
To calculate BMI, we use the following formula:
BMI = weight (kg) / height² (m)
For example: if someone weighs 70 kg and is 170 cm tall, then BMI = 70 / (1.7 × 1.7) = 24.2
BMI Categories and their meaning
| BMI Range | Category | Health Risk |
|---|---|---|
| Below 18.5 | Underweight | Risk of underweight |
| 18.5-24.9 | Normal weight | Low risk |
| 25-29.9 | Overweight | Moderate risk |
| 30-34.9 | Obesity (Class I) | High risk |
| 35-39.9 | Obesity (Class II) | Very high risk |
| Above 40 | Severe obesity (Class III) | Critical risk |
BMI and health
BMI is an important health indicator, but not the only one. It is important to understand that BMI does not take into account muscle mass, bone density, or other health factors.
Limitations of BMI
- Does not take into account muscle mass
- Does not take into account bone density
- Does not take into account body fat distribution
- Does not take into account age
- Does not take into account sex
When to use the BMI calculator?
The BMI calculator is a useful tool in the following situations:
- Assessing and tracking body weight
- Setting weight loss or weight gain goals
- Assessing health risks
- Developing a diet and exercise plan
- Preparing for a medical consultation
Frequently asked questions
How often should I calculate my BMI?
It is recommended to calculate your BMI once a month to track changes. However, do not use it too frequently, as daily fluctuations can be confusing.
Is BMI accurate?
BMI is a good guideline, but not perfect. Athletes with a lot of muscle mass may show a higher BMI, even though they are healthy. Always consult your doctor regarding questions about your weight.
What is the normal BMI range?
The normal BMI range is between 18.5 and 24.9. This range represents the lowest health risk for most people.
Related calculators
Check out our other health calculators:
- Calorie Calculator – Calculate daily calorie needs
- Body Fat Calculator – Determine body fat percentage
- Ideal Weight Calculator – Calculate target weight
- TDEE Calculator – Total daily energy expenditure
Medical advice
Important: The BMI calculator is only a guideline and does not replace medical advice. If you are concerned about your weight, always consult your doctor or a nutrition expert. This is especially important if:
- You have chronic diseases
- You are pregnant or breastfeeding
- You are an athlete or have a large amount of muscle mass
- You are younger than 18 or older than 65
Use our calculator responsibly, and always consult a professional regarding questions about your weight. Health is the most important thing!