# Body Mass Index (BMI) Calculator

The Body Mass Index (BMI) helps in calculating the height-to-weight ratio of a person. The score determines if a person is at his/her healthy weight or needs to shed or gain more kilos. A BMI calculator is widely used as a general tool to assess if a person has a healthy body weight proportional to their height.

### What Is BMI?

BMI stands for Body Mass Index. A person’s BMI is calculated by dividing their weight in kilograms by the square of height in metres. It is an effective and easy way to calculate whether or not someone is at their ideal weight.

BMI provides an idea of the amount of fat someone may have and if any changes are required. Being able to calculate whether someone is obese, underweight, overweight or at their ideal weight helps measure the risk of other illnesses. An unhealthy weight might make one prone to a range of chronic and lifestyle diseases. Several lifestyle diseases are tied to obesity while being underweight also poses health risks.

### What Is Ideal BMI For Men And Women?

The BMI calculation remains the same for everyone over the age of 20. BMI is calculated by the height and weight of the given person. The ideal BMI range for men and women is between 18.5 to 24.9. Anything below 18.5 would be considered underweight while 25.0 and over is considered overweight. A BMI of 30.0 and above is considered obese.

This range is wide and where you are placed on this range in accordance with your height can help you better understand whether or not you are at a healthy weight.

### BMI Categories

Below 18.5 - Underweight

18.5-24.9 - Normal

25.0-29.9 - Overweight

30.0 and higher - Obese

### BMI Formula

Below are the formulae for calculating BMI as per the the International System of Units (SI) and the US customary system (USC):

BMI = weight ÷ height in meters squared

Metric units: BMI = weight (kg) ÷ height in meters squared

US units: BMI = weight (lb) ÷ height in inches squared * 703

Note that BMI cannot be the only marker of your health and fitness level. It is always ideal to speak to a health professional to better understand whether or not you are at the right weight and factors that could be affecting your weight other than diet and lifestyle.