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Check your Body‑Mass Index
What is BMI? Body Mass Index (BMI) is a simple health indicator that helps you understand if your weight is healthy for your height. It is widely used by doctors and health professionals to screen for weight categories that may lead to health problems.
How to Use This Calculator
- Select your preferred unit system: Metric (cm/kg) or Imperial (ft/in/lbs).
- Enter your height and weight in the fields provided.
- Click Calculate BMI to see your result instantly.
Example: If you are 170 cm tall and weigh 65 kg, your BMI will be 22.5, which is considered a normal weight.
Why Does BMI Matter?
BMI is a quick way to check if you are underweight, normal weight, overweight, or obese. Maintaining a healthy BMI can reduce your risk of heart disease, diabetes, and other health issues. However, BMI does not measure body fat directly and may not be accurate for athletes or those with high muscle mass.
Frequently Asked Questions
- Is BMI accurate? BMI is a useful screening tool but does not account for muscle mass, bone density, or overall body composition.
- Can children use this calculator? BMI calculations for children and teens use different criteria.Please consult a pediatrician for accurate assessment.
- What should I do if my BMI is high? Consider speaking with a healthcare provider for personalized advice on diet, exercise, and lifestyle changes.
Use Cases
- Screen your current weight category before starting a fat-loss or strength program.
- Track BMI changes monthly when working with a doctor or dietitian.
- Estimate health-risk brackets for insurance or workplace wellness forms.
Worked Examples
Example 1: Height 170 cm and weight 72 kg gives BMI = 72 / (1.70 × 1.70) = 24.9 (upper end of healthy range).
Example 2: Height 165 cm and weight 92 kg gives BMI = 92 / (1.65 × 1.65) = 33.8 (obesity class I).
Common Mistakes
- Mixing units (entering inches as centimeters or pounds as kilograms).
- Using BMI alone for athletes with high muscle mass.
- Comparing day-to-day changes instead of long-term trends.
Pro Tips / Expert Tips
- Pair BMI with waist measurement for a clearer metabolic risk picture.
- Re-check under similar conditions (same time of day, same scale).
- Use 3-month rolling averages instead of single weigh-ins.
Internal Linking
Also try the Calories Burned Calculator and Loan Payment Calculator. For deeper reading, see BMI Ranges Explained and Science Behind BMI vs Body Fat.
Want to understand what your number means? Read our BMI Ranges Explained guide.
BMI categories
- Underweight: < 18.5
- Normal weight: 18.5 – 24.9
- Overweight: 25 – 29.9
- Obesity: ≥ 30
Last updated 15 Jun 2025