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BMI Calculator

Q: What is a healthy BMI range?

For most adults, a healthy BMI range is between 18.5 and 24.9. BMIs below 18.5 indicate underweight, and BMIs above 25.0 indicate overweight.

Q: Does BMI apply to kids and teenagers?

While the same basic formula is used, children's BMI is evaluated using percentiles relative to other children of the same age and biological sex, as body fat composition changes rapidly during growth.

Q: Is BMI accurate for active athletes?

No. Muscle is denser than fat, so muscular individuals often have high BMIs despite having low body fat percentages. For athletes, body fat percentage or waist circumference are better health markers.

Calculate your Body Mass Index (BMI) using metric or imperial units and learn your weight status category.

Body Dimensions

Age Group

Unit System

Height

Weight

lbs

BMI Results

Your Calculated BMI

0.0

Category: Normal

UnderweightNormalOverweightObese

< 18.518.5 - 24.925.0 - 29.930.0 +

How to Calculate & Formula Details

Mathematical Model FormulaBMI = weight (kg) / height² (m²). In imperial: BMI = 703 * weight (lbs) / height² (inches²).

A Body Mass Index (BMI) calculator estimates a person's body fat based on their height and weight. While it does not measure body fat directly, it is a simple and widely accepted screening tool used by healthcare providers to classify body weight categories.

Standard BMI Categories for Adults

Underweight: BMI below 18.5
Normal weight: BMI between 18.5 and 24.9
Overweight: BMI between 25.0 and 29.9
Obese: BMI of 30.0 or higher

Limitations of BMI

BMI is a general estimate and does not take muscle mass, bone density, or body composition into account. For instance, athletes and bodybuilders with high muscle mass may have a high BMI that classifies them as "overweight" or "obese" despite having very low body fat.

Frequently Asked Questions

What is a healthy BMI range?

For most adults, a healthy BMI range is between 18.5 and 24.9. BMIs below 18.5 indicate underweight, and BMIs above 25.0 indicate overweight.

Does BMI apply to kids and teenagers?

While the same basic formula is used, children's BMI is evaluated using percentiles relative to other children of the same age and biological sex, as body fat composition changes rapidly during growth.

Is BMI accurate for active athletes?

No. Muscle is denser than fat, so muscular individuals often have high BMIs despite having low body fat percentages. For athletes, body fat percentage or waist circumference are better health markers.

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