BMI Calculator
What is a BMI Calculator?
A Body Mass Index (BMI) Calculator is a tool used to estimate a person's body fat based on their weight and height. It provides an indication of whether an individual has a healthy body weight for a given height. BMI is widely used as a simple method to categorize individuals into different weight categories such as underweight, normal weight, overweight, and obese.
How to Calculate BMI
The formula is BMI = kg/m2 where kg is a person’s weight in kilograms and m2 is their height in metres squared.
A BMI of 25.0 or more is overweight, while the healthy range is 18.5 to 24.9. BMI applies to most adults 18-65 years.
BMI Table for Adults
Here is the BMI classification for adults aged 20 and older:
| BMI Range | Weight Status |
|---|---|
| Below 18.5 | Underweight |
| 18.5 - 24.9 | Normal weight |
| 25.0 - 29.9 | Overweight |
| 30.0 and above | Obese |
BMI Chart for Adults
Below is a simplified BMI chart for adults. You can find your height in the left column and move across to find your weight to determine your BMI category.
| Height (in) | Weight (lbs) for BMI 18.5 | Weight (lbs) for BMI 24.9 | Weight (lbs) for BMI 29.9 | Weight (lbs) for BMI 30.0 |
|---|---|---|---|---|
| 58 | 91 | 119 | 143 | 144 |
| 60 | 97 | 127 | 153 | 154 |
| 62 | 104 | 136 | 164 | 165 |
| 64 | 110 | 144 | 174 | 175 |
| 66 | 118 | 154 | 186 | 187 |
| 68 | 125 | 164 | 197 | 198 |
| 70 | 132 | 174 | 209 | 210 |
| 72 | 140 | 184 | 221 | 223 |
| 74 | 148 | 194 | 233 | 235 |
| 76 | 156 | 205 | 246 | 247 |
BMI Table for Children and Teens, Age 2-20
For children and teens, BMI is interpreted differently than it is for adults. BMI is age- and sex-specific and is often referred to as BMI-for-age. The BMI percentiles are used to classify weight status:
| BMI Percentile | Weight Status |
|---|---|
| Less than the 5th percentile | Underweight |
| 5th to less than the 85th percentile | Normal weight |
| 85th to less than the 95th percentile | Overweight |
| 95th percentile and above | Obese |
BMI Chart for Children and Teens
BMI-for-age percentiles are plotted on standardized growth charts that are specific to age and sex. These charts are available from the Centers for Disease Control and Prevention (CDC). Below is a simplified version of what these charts generally represent:
For Boys:
| Age (Years) | Underweight (BMI < 5th Percentile) | Normal Weight (BMI 5th-85th Percentile) | Overweight (BMI 85th-95th Percentile) | Obese (BMI > 95th Percentile) |
|---|---|---|---|---|
| 2 | < 14.8 | 14.8 - 18.4 | 18.4 - 20.1 | > 20.1 |
| 4 | < 14.0 | 14.0 - 17.3 | 17.3 - 18.8 | > 18.8 |
| 6 | < 13.5 | 13.5 - 16.8 | 16.8 - 18.2 | > 18.2 |
| 8 | < 13.4 | 13.4 - 17.5 | 17.5 - 19.1 | > 19.1 |
| 10 | < 13.5 | 13.5 - 18.9 | 18.9 - 20.7 | > 20.7 |
| 12 | < 14.1 | 14.1 - 20.9 | 20.9 - 23.0 | > 23.0 |
| 14 | < 15.2 | 15.2 - 23.4 | 23.4 - 25.8 | > 25.8 |
| 16 | < 16.2 | 16.2 - 25.5 | 25.5 - 28.1 | > 28.1 |
| 18 | < 17.2 | 17.2 - 27.0 | 27.0 - 29.7 | > 29.7 |
| 20 | < 18.1 | 18.1 - 28.1 | 28.1 - 30.9 | > 30.9 |
For Girls:
| Age (Years) | Underweight (BMI < 5th Percentile) | Normal Weight (BMI 5th-85th Percentile) | Overweight (BMI 85th-95th Percentile) | Obese (BMI > 95th Percentile) |
|---|---|---|---|---|
| 2 | < 14.6 | 14.6 - 18.0 | 18.0 - 19.8 | > 19.8 |
| 4 | < 13.9 | 13.9 - 17.2 | 17.2 - 18.8 | > 18.8 |
| 6 | < 13.4 | 13.4 - 16.8 | 16.8 - 18.4 | > 18.4 |
| 8 | < 13.4 | 13.4 - 17.5 | 17.5 - 19.1 | > 19.1 |
| 10 | < 13.7 | 13.7 - 18.9 | 18.9 - 20.8 | > 20.8 |
| 12 | < 14.5 | 14.5 - 21.1 | 21.1 - 23.3 | > 23.3 |
| 14 | < 15.7 | 15.7 - 23.7 | 23.7 - 26.1 | > 26.1 |
| 16 | < 16.8 | 16.8 - 25.6 | 25.6 - 28.2 | > 28.2 |
| 18 | < 17.5 | 17.5 - 26.7 | 26.7 - 29.4 | > 29.4 |
| 20 | < 18.2 | 18.2 - 27.6 | 27.6 - 30.3 | > 30.3 |