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BMI Calculator - Body Mass Index Calculator

Calculate Body Mass Index online and assess weight health status

Metric/Imperial
Visual scale
Ideal weight
Health assessment
Input Data
Your BMI
NaN
Obese Class III
1518.52530354045
Recommendations
Healthy Weight RangeNaN - NaN kg
Ideal WeightNaN kg
BMI Categories
Underweight
< 18.5
Normal
18.5 - 24.9
Overweight
25 - 29.9
Obese Class I
30 - 34.9
Obese Class II
35 - 39.9
Obese Class III
≥ 40

BMI Calculator helps you quickly calculate your Body Mass Index to assess whether your weight is within a healthy range. Supports both metric (kg/cm) and imperial (lbs/ft) units with visual indicators and personalized healthy weight recommendations.

What is BMI?

BMI (Body Mass Index) is a simple numerical measure calculated from your weight and height using the formula: weight(kg) ÷ height(m)². It's widely used by healthcare professionals as a quick screening tool to categorize weight status in adults.

BMI Categories

  • Underweight: BMI below 18.5 - May indicate nutritional deficiency
  • Normal: BMI 18.5-24.9 - Generally associated with good health
  • Overweight: BMI 25-29.9 - Increased health risks
  • Obese: BMI 30+ - Significantly elevated health risks (Class I, II, III)

Limitations of BMI

While BMI is a useful screening tool, it has limitations. It doesn't distinguish between muscle and fat, so athletes may show high BMI despite being healthy. It also doesn't account for age, gender, ethnicity, or fat distribution. BMI should be used alongside other health indicators, not as a sole diagnostic tool.

FAQ

Q: Is a normal BMI always healthy?

A: Not necessarily. BMI doesn't measure body composition, visceral fat, or overall fitness. Someone with normal BMI might still have unhealthy body fat distribution. It's best used as one of several health indicators.

Q: Why do athletes often have high BMI?

A: Muscle is denser than fat. Athletes with significant muscle mass may have a BMI in the 'overweight' range while having very low body fat. For them, body fat percentage is a better metric.

Q: Does BMI apply to children?

A: Children and teenagers need age and sex-specific BMI percentiles rather than standard adult categories. Their body composition changes significantly during growth, requiring specialized growth charts.