Health and Fitness Calculators
Body Mass Index (BMI)
Body Mass Index is a measurement of body fat based on your characteristics. It’s a simple metric but gives you a good read into your overall weight and is a great value to set weight goals around.
If you track your weight online, FitnessSyncer can provide you the BMI automatically as long as you provide your height in your profile and you can set and easily keep an eye on your weight goals.
Based on the above, your Body Mass Index is 0. A BMI between 18.5 and 24.9 is considered normal.
How it works
Body mass index divides your weight by the square of your height, which puts people of different heights on one scale. The squaring is what makes it a comparison rather than just your weight.
BMI = weight in kilograms ÷ (height in meters)²
Someone 1.75 m tall weighing 70 kg has a BMI of 70 ÷ (1.75 × 1.75), which is 22.9.
The categories
| BMI | Category |
| Under 18.5 | Underweight |
| 18.5 to 24.9 | Normal |
| 25.0 to 29.9 | Overweight |
| 30.0 and above | Obese |
What this number is not
It is not a measure of body fat, and it cannot tell muscle from anything else. A heavily built athlete and someone carrying the same weight as fat get the same BMI, which is the single most important thing to know about it.
How accurate it is
BMI was designed to describe populations rather than individuals, and it does that well. For one person it is a rough first look, and body fat percentage or lean body mass from a smart scale says far more.
Common questions
Is BMI useful if I lift weights?
Much less so. Muscle is denser than fat, so a muscular build pushes BMI up without anything being wrong. Track your body fat percentage or your lean body mass instead, both of which FitnessSyncer reads from a connected smart scale.
Does FitnessSyncer work out my BMI automatically?
Yes, as soon as your height is in your profile and a weight has arrived from a connected scale or the Notebook. It appears on your Dashboard and you can set a goal against it.
Does BMI differ for men and women?
The formula does not, and neither do the standard categories. Body composition at the same BMI does differ, which is another reason to look at body fat percentage where you have it.
