BMI Calculator

BMI Calculator | Accurate Body Mass Index Measurement

Body Mass Index (BMI) is a widely used tool to estimate a person’s body fat based on their weight and height. It helps assess whether you are underweight, normal weight, overweight, or obese. The BMI Calculator makes this quick, accurate, and easy to understand.

Why BMI Measurement is Important

• Health Assessment: Helps identify weight-related health risks.
• Fitness Planning: Useful for setting realistic goals in weight management.
• Medical Guidance: Doctors use BMI to monitor patients’ health.
• Education: Teaches how weight and height relate to body composition.

BMI Formula

The formula for BMI is simple and depends on the unit system:

• Metric Units: BMI = Weight (kg) / (Height (m))²
• Imperial Units: BMI = (Weight (lb) / (Height (in))²) × 703

How the BMI Calculator Works

1. Enter your weight in kilograms or pounds.
2. Enter your height in meters or inches.
3. The calculator applies the BMI formula automatically.
4. Instantly receive your BMI value and classification.

BMI Classification

BMI Range	Category
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
40 and above	Obesity Class III

Step-by-Step Example 1: Metric Units

Problem: Weight = 70 kg, Height = 1.75 m.
Formula: BMI = Weight / Height²
Calculation: BMI = 70 / (1.75 × 1.75) = 70 / 3.0625 = 22.86
Category: Normal weight

Step-by-Step Example 2: Imperial Units

Problem: Weight = 160 lb, Height = 65 in.
Formula: BMI = (Weight / Height²) × 703
Calculation: BMI = (160 / (65 × 65)) × 703 = (160 / 4225) × 703 ≈ 26.6
Category: Overweight

FAQs – BMI Calculator

1. What is BMI?
Body Mass Index is a numerical value that estimates body fat based on weight and height.

2. Is BMI accurate for everyone?
BMI is a useful screening tool, but it may not perfectly reflect body fat for athletes or muscular individuals.

3. Can children use BMI?
For children, BMI percentiles based on age and sex are used instead of standard adult ranges.

4. Can I use metric or imperial units?
Yes, the calculator supports both kilograms/meters and pounds/inches.

5. Does BMI indicate health risks?
BMI provides a general risk assessment for conditions like heart disease, diabetes, and high blood pressure.

6. Can I convert BMI to body fat percentage?
BMI gives an estimate, but additional formulas or measurements are needed for precise body fat percentage.

7. How often should I calculate BMI?
Regular monitoring is helpful, especially during weight loss or fitness programs.

8. Is this calculator free?
Yes, it’s completely free and works on all modern browsers.

9. Can BMI change with age?
Yes, BMI tends to increase with age due to changes in muscle mass and fat distribution.

10. Is this tool suitable for medical guidance?
BMI is a screening tool. Consult a healthcare professional for medical advice.