BMI Calculator

What is BMI?

Body Mass Index, or BMI, is a simple method used to measure body weight in relation to height. A Free BMI Calculator Check Your Body Mass Index tool helps calculate BMI value using height and weight measurements in kg and cm. It is commonly used to identify whether a person falls into a healthy BMI range, underweight category, overweight category, or obese category. 

$$\text{BMI}=\frac{\text{Weight (kg)}}{\left(\text{Height (m)}\right)^2}$$

Variables Explained

• Weight (kg) = Body weight in kilograms
• Height (m) = Height in meters
• BMI = Body Mass Index Healthcare providers and the World Health Organization use BMI measurement as a general health indicator for adults, children, and teens.

Metric Formula: The metric BMI formula uses kilograms and meters to calculate Body Mass Index (BMI). It is the standard formula used by healthcare organizations and medical professionals worldwide.

$$\text{BMI}=\frac{\text{Weight (kg)}}{\left(\text{Height (m)}\right)^2}$$

Imperial Formula: The imperial BMI formula uses pounds and inches instead of metric units. This method is commonly used in the United States.

$$\text{BMI}=703\times\frac{\text{Weight (lb)}}{\left(\text{Height (in)}\right)^2}$$

BMI Categories and chat

Underweight

A BMI below 18.5 places you in the underweight category. Being underweight can increase the risk of nutrient deficiencies, low energy levels, and weakened immunity.

Normal Weight

A BMI between 18.5 and 24.9 indicates a healthy weight range. Maintaining a healthy weight supports overall wellness and helps reduce the risk of chronic diseases.

Overweight

A BMI between 25 and 29.9 places you in the overweight category. Carrying extra body weight can increase the risk of high blood pressure, diabetes, and other health conditions.

Obesity

A BMI of 30 or higher places you in the obesity category. Excess body weight can increase the risk of heart disease, stroke, certain cancers, and other serious health problems.

BMI Chart for Adults, Men, Women, Teen and Children

Body Mass Index (BMI) helps estimate whether a person's weight falls within a healthy range based on height and weight. While BMI categories are generally the same for adults, BMI for teens and children is evaluated using age- and sex-specific growth percentiles.

*For children and teens (ages 2–19), BMI is interpreted using age- and sex-specific growth charts rather than standard adult BMI ranges.

Alternative Health Measurements

BMI is a useful screening tool, but other body measurements can provide a more detailed view of body composition, fat distribution, and overall health risk.

Waist Circumference

Waist circumference measures abdominal fat around the stomach area and helps identify obesity-related health risks such as cardiovascular disease, metabolic syndrome, and Type 2 diabetes.

Although no formula is required, waist circumference is measured directly around the abdomen using a measuring tape.

Waist-to-Hip Ratio (WHR)

Waist-to-Hip Ratio compares waist size to hip size to evaluate fat distribution and metabolic health risk more accurately than body weight alone.

$$\text{WHR}=\frac{\text{Waist Circumference}}{\text{Hip Circumference}}$$

Higher WHR values may indicate a greater risk of cardiovascular and metabolic diseases.

Body Fat Percentage

Body fat percentage estimates how much of the body consists of fat tissue compared to lean body mass.

$$\text{Body Fat Percentage}= \frac{\text{Fat Mass}}{\text{Total Body Weight}} \times 100$$

This measurement provides a more direct assessment of body composition than BMI alone.

Skinfold Thickness

Skinfold thickness testing uses measurements from different body locations to estimate total body fat levels and physical fitness status.

The method involves measuring skinfold thickness with calipers at standardized body sites and applying body-fat estimation equations.

$$\text{Body Density}=\text{Function of Skinfold Measurements}$$

Skinfold assessments are commonly used in fitness, sports science, and health evaluations to estimate body fat percentage.