What is BMI and how is it calculated?

BMI (Body Mass Index) is calculated by dividing your weight in kilograms by your height in meters squared. The formula is BMI = weight(kg) / height(m)². It's a screening tool to categorize weight status and check your body bmi.

What are the BMI categories?

BMI categories are: Underweight (below 18.5), Normal weight (18.5-24.9), Overweight (25-29.9), and Obese (30 or higher). These ranges apply to adults aged 20 and older. See our BMI range chart for visual reference.

Is BMI accurate for everyone?

BMI is a screening tool, not a diagnostic measure. It may not be accurate for athletes with high muscle mass, elderly people, pregnant women, or children. For a more complete picture, also check your body fat index using our body fat estimator.

What is a healthy BMI range?

A healthy BMI range is typically between 18.5 and 24.9. This range is associated with lower risk of weight-related health conditions like heart disease, diabetes, and high blood pressure.

How is body fat percentage calculated?

Our body fat estimator uses the U.S. Navy Method which calculates body fat percentage based on neck, waist, and hip measurements. This provides a more accurate picture of your body composition than BMI alone.

BMI Calculator & Body Fat Estimator

Check your Body Mass Index (BMI) and estimate your body fat percentage to understand your body composition. Use our BMI chart calculator to see where you fall in the BMI range.

Units

Metric (kg, cm) Imperial (lbs, ft/in)

Weight (kg) Height (cm)

Personal Info Age Gender (required for body fat)

Body Fat Estimation (Optional - Navy Method)

Add these measurements for a more complete body composition analysis.

Neck Circumference (cm) Waist Circumference (cm)

Your BMI results will appear here.

BMI Range Chart

Use this visual BMI chart to quickly check your BMI category. The body mass index ranges are color-coded for easy reference.

BMI Range	Category	Health Risk
< 18.5	Underweight	Increased risk of nutritional deficiency
18.5 - 24.9	Normal Weight	Low risk - healthy range
25.0 - 29.9	Overweight	Moderate risk of health issues
30.0 - 34.9	Obese Class I	High risk of health issues
35.0 - 39.9	Obese Class II	Very high risk of health issues
≥ 40.0	Obese Class III	Extremely high risk of health issues

Understanding Body Fat Index

While BMI is a useful screening tool for body mass index, it doesn't directly measure body fat. Our body fat estimator uses the U.S. Navy Method to calculate your body fat percentage based on circumference measurements.

Body Fat Percentage Categories

Men

2-5% Essential Fat
6-13% Athletes
14-17% Fitness
18-24% Average
25%+ Obese

Women

10-13% Essential Fat
14-20% Athletes
21-24% Fitness
25-31% Average
32%+ Obese

How to Measure

Neck: Measure at the narrowest point, below the larynx
Waist: Measure at the navel level for men, at the narrowest point for women
Hips (women only): Measure at the widest point of the buttocks

BMI vs Body Fat: What's the Difference?

Your body BMI (Body Mass Index) is a simple calculation based on height and weight. While useful for general screening, BMI doesn't distinguish between muscle and fat mass. This is why athletes with high muscle mass may have a high BMI but low body fat.

For a complete picture of your health, we recommend checking both your BMI and body fat index. Together, these metrics provide better insight into your body composition and potential health risks.

Note: These are screening tools only. Always consult a healthcare provider for personalized health assessment and advice.

RECOMMENDED APP