Measure Your Body

In addition to our breathing and posture features, Prana’s unique retractable design allows you to accurately track 15 distinct body measurements including your body fat percentage. These are:

  • Waist
  • Chest
  • Neck
  • Shoulders
  • Left and right Biceps
  • Left and right Forearms
  • Left and right Wrists
  • Left and right Thighs
  • Left and right Calves
  • Body Fat percentage

As discussed below, our body measurements and muscle mass are intimately connected to many important aspects of our health, wellness, and even longevity, which is why we felt it essential to include this feature in our wearable.

Taking Measurements with Prana

Using a traditional tape measure is often inconvenient, requiring a 3rd hand or another person to hold it, especially around areas like biceps or the neck. Consistency of measurement is another issue, as well as tracking all the data.

Prana’s novel loop-lock design makes it much easier to take quick and consistent measurements with a single hand, and to graphically see your progress in our app. Our retractable belt can measure up to 59” (150cm).

How We Carry Body Fat Matters

Numerous medical studies have found that how fat is distributed in our body, in particular around our waist and midsection, significantly increases the risk of many adverse health issues including diabetes, heart attacks, insulin resistance, metabolic syndrome, fatty liver, and even cancer. Fat surrounding the liver and other abdominal organs is highly metabolically active, releasing inflammatory agents and hormones which can increase many negative health markers such as LDL cholesterol, triglycerides, blood pressure, and blood glucose. It’s been found that if most of your fat is stored around your waist rather than at your hips, you’re at a higher risk for heart disease and type 2 diabetes. According to another study, excess belly fat is associated with higher risk of death from any cause.

Use Prana to Track Waist and Hip Size

Prana can accurately track both your waist and hip size over time to help you stay or get into a healthy range. Using a standard weight scale unfortunately doesn’t tell you much about fat distribution in your body, and same goes for calculating your BMI (body mass index) which only takes into account your height and weight.

Use Prana to Track Body Fat Percentage

Prana can also track your overall body fat percentage to within 2 - 4% accuracy. In addition to waist size, body fat is an important measure for assessing fitness and health. Multiple studies have found that higher overall body fat increases the risk for multiple obesity-related diseases including heart attacks, stroke, high blood pressure, and type 2 diabetes.

From a study in the American Journal of Clinical Nutrition:

Body Fat Target Guidelines



Healthy Body Fat % (Women)


Healthy Body Fat % (Men)


By measuring your waist, neck, and hip size (takes about a minute to do), Prana is able to accurately estimate and chart your body fat % utilizing the US Navy Body Fat Formula standard.

Use Prana to Track Your Muscle Mass and Body Composition

Muscle mass is associated with longevity. Recent studies have found that muscle mass correlates with a decrease in all-cause mortality. Muscles help us control glucose levels and are essential from a metabolic perspective. As we age, our strength and muscles tend to decline. Sarcopenia--the decline of skeletal muscle tissue with age—is a very important contributor to loss of independence and functional decline in older adults. Sarcopenia can start to appear as early as our 40’s, and can lead to fatigue, frailty, risk of falls, and death.

This is why we engineered Prana to be able to measure and track all major muscles of the body. By knowing baseline

sizes of all your major muscles, you are in a better position to both prevent loss of this lean tissue, and also more informed for how to adjust your diet, resistance, and aerobic training programs. If you’re a more advanced fitness or body builder enthusiast, Prana makes it easy to accurately track your gains with consistency and convenience.

It’s hard to improve what we aren’t measuring; Undesired changes can sneak up on us. Taking your body measurements just a few times per month can help you keep moving in a healthier direction. Knowing your waist size, body fat percentage (hence lean body mass), and sizes of your major muscles gives you a critical snapshot for very important and highly actionable aspects of your health and wellness.