Biacromial breadth

The width between your shoulders can vary according to genetics, weight, body type, and other factors. The researchers who study human measurement, called anthropometry, have developed metrics and methods for measuring the width of your shoulders. The official term used to describe this measurement is “biacromial breadth” or “biacromial diameter.”

Keep reading to find out what shoulder width averages have looked like over time and how to measure your own shoulder width.

If “biacromial diameter” sounds like an outdated term to you, that’s because it is. It probably isn’t used as much as it used to be. That might be in part because the United States hasn’t published an official shoulder width average in over 30 years.

This presents some challenges in figuring out the average shoulder width for U.S. men and women today. Most of the data we have about current average shoulder width is anecdotal.

In contrast, the Centers for Disease Prevention and Control (CDC) continue to publish detailed breakdowns of average height, weight, BMI, and other body measurements broken down by ethnicity, age, and height.

Anecdotal observations tell us that shoulder width averages can vary according to ethnicity, diet, exercise, and family history. Statistics tell us that men and women are getting taller and wider worldwide. Here’s what we know:

Survey data taken in the early 1960s calculated that 3,581 American women over the age of 17 had an average shoulder width of 13.9 inches (35.3 cm). Men had an average shoulder width of 15.6 inches (39.6 cm), based on 3,091 survey participants. But things have changed since then.

CDC survey data from 1988 to 1994 summarizes biacromial measurements taken of 8,411 women aged 20 years and older. Based on their measurements, the average shoulder width for American women was 14.4 inches (36.7 cm). Based on the shoulder measurements of 7,476 men aged 20 years and older taken during the same time period, the average shoulder width of men in the United States was 16.1 inches (41.1 cm).

A bit different than strictly biacromial width, some measurements span from arm-to-arm. A 1988 survey of United States military personnel tallied the average forearm-to-forearm breadth (tricep-to-tricep) for men as 21.5 inches (54.6 cm).

This survey measured the shoulder breadth of 1,774 males over the age of 19, and all participants were military personnel. The same survey calculated 2,208 female participants to have an average forearm-to-forearm breadth of 18.4 inches (46.8 cm).

The forearm-to-forearm breadth measurement tends to be wider than the standard measurement of shoulder-blade-to-shoulder blade (biacromial breadth).

A 2009 survey conducted in Sweden showed the average shoulder width calculated for 105 men over 18 was 15.5 inches. Out of 262 women measured, the average shoulder breadth was 14 inches. This survey concluded that average human dimensions had increased for the Swedish population over the past 40 years.

If you’re interested in how you measure up to historic averages, grab a friend and a tape measure for the easiest way to know your shoulder width.

The official way to measure your shoulder width is to measure joint-to-joint from shoulder tip to shoulder tip. This can be done with your back facing your friend who holds up a measuring tape.

Measuring your shoulders with help

Instruct your friend to place the end of the measuring tape at the place where your shoulder meets the top of your arm, or, the boniest part of your shoulder. From there, holding the tape taut, they should stretch the tape straight across to the tip of your other shoulder blade. The measurement is your shoulder width.

Measuring your shoulders by yourself

If you’re by yourself and want to measure your shoulders, stand against a wall with your head held high. Using a pencil, reach across your left shoulder with your right hand and mark the place right above your shoulder joint. Repeat the process on the opposite side with your opposite hand. Then use a measuring tape to measure the distance between the two markings.

This is a much easier measurement to get if you have someone with you!

To measure your shoulders from arm-to-arm, an anthropometrist would use big calipers to measure the breadth of your shoulders including your arms. To replicate this, stand facing a partner and use a measuring tape to get this measurement.

Let your arms hang relaxed, down at your sides. Try to keep your posture as upright as possible but also still relaxed. Have the other person measure across you from the tops of your upper arms. Depending on the contours of your body, this measurement may be easier to take or more accurate if measured across your back rather than your front.

Shoulder breadth on its own may not say as much as when it’s combined with other body measurements. Researchers take these measurements for all sorts of reason. They take body measurements to understand growth patterns and health of a population and to apply measurements to the design of the spaces we use — from cars to chairs to assistive devices. It’s even how the width of your shirt gets sized and how a tailor makes clothes fit better.

Average shoulder width has changed slightly over the years and without more recent measurements of a large sample of different populations it’s hard to know what the current average shoulder width is.

Still, based on biacromial measurements taken in years passed and trends observed by researchers, it’s probably safe to say that in the United States average shoulder width is at least 16 inches (41 cm) for men and 14 inches (36 cm) for women.

Depending on what the measurement is being used for, how shoulder width is measured may vary.