BMI, or Body Mass Index, is what people used to base on to define if your body was in good and healthy condition. It was widely used to evaluate physical fitness. You can use this calculator to see what your BMI is. But is BMI really a good way to evaluate our bodies?

If your BMI is under 18.5, you are underweight.

A BMI of 30 or above means you're obese.

BMI doesn't take into account the percentage of muscle, fat, and bone, which can actually dramatically change your appearance.

Body Labs has done body scans of 6 different women, all of who are 5'7", weighing 145lbs, with a "normal" BMI of 22.8.

The graphic above shows you each of them have different body shapes. So what does BMI actually tell us?

"You can be an athlete in great shape and be deemed overweight or even obese," says Jonathan Schwartz, the director of products at Body Labs. "Or you could have an average BMI but carry a significantly higher amount of mass in your torso, which as some studies show can be a predictor of health risks such as cardiovascular disease or diabetes.