How to Calculate the Body Mass Index Using the Metric System

Overview

Body fat percentage, flexibility, muscle endurance, cardiovascular strength and body mass index (BMI) are all fitness parameters. Your BMI is a relationship of your height to your weight, and doctors use this measurement to determine your risks for various health conditions. There are several steps you can follow in order to figure out your body mass index using the metric system.

Step 1

Determine your weight in kilograms. The first thing you need to do is find your weight in pounds and convert it to kilograms. Weigh yourself first thing in the morning on an empty stomach and right after using the bathroom. This will give you your most accurate weight. One pound equals .4536 kilograms. As an example, if you weigh 160 pounds, you will weigh 72.58 kilograms.

Step 2

Determine you height in meters squared. To find your height, stand with your back against a wall or open doorway. Place a mark on the wall at the height of your head. Measure the distance in inches. One inch equals .0254 meters. As an example, if you are 62 inches tall, you will be 1.57 meters tall. Once you square it, you get 2.48 meters.

Step 3

Use the formula for calculating BMI. The equation for body mass index in the metric system is weight in kilograms divided by height in meters squared. Using the above numbers for an example, it would look like this: 72.58/ (1.57 * 1.57). Your BMI would be 29.27.

Step 4

Check your results. After you have found your BMI, you can compare your results to the chart to see what category you fall into. If you are less than 18.5, you are underweight. A body mass index of 18.5 to 24.9 is normal. If your BMI is 25-29.9, you are considered overweight. Anything above 30 is considered obese. (The BMI found in step three would be considered overweight.)