How to Measure Forearms

Forearm size can be determined using various methods, such as measuring the length and circumference.

According to anthropometric surveys, forearm length is the linear distance between the elbow and wrist bones. On the other hand, forearm circumference is the distance around the widest part of the forearm while it is flexed. 

To measure the length of your forearm, stand with your arm relaxed straight down by your side with your palm facing forward. Use a tape measure or beam caliper to measure the distance between the elbow and wrist bones. This may require assistance from another person.

To measure the circumference of your forearm, stand with your upper arm extended forward horizontally and your elbow flexed at a 90° angle. Clench your fist tightly with your palm facing your head. Use a flexible tape to measure the distance around the widest part of your forearm.

Average Forearm Size Statistics

In 2012, the US Army conducted measurements of over 6,000 military men and women to determine their body size. The measurements included forearm length and forearm circumference.

This data offers an intriguing insight into the average forearm size of relatively healthy adults. Let’s take a look at the numbers!

Average Forearm Length

According to the 2012 anthropometric survey, the average forearm length was 10.5 inches (26.7 cm) for men and 9.5 inches (24.0 cm) for women.

However, there is considerable variation in forearm length, mainly due to height. To illustrate, the table below shows forearm length percentiles for both genders. The 50th percentile is the average forearm size, while lower is smaller and higher is bigger.

Average Forearm Circumference

On average, men have a forearm circumference of 12.2 inches (31.0 cm), while women’s forearms average 10.4 inches (26.3 cm) in circumference. These measurements are with the forearm flexed.

It’s important to note that there’s a significant range in forearm sizes on either side of the average. To help you understand what’s considered large or small, Table 2 below displays forearm measurements as percentiles.

Forearm Size & Proportions

How big or small your forearms appear is also a matter of proportion to your body. For example, longer bones tend to make your forearms look skinny. So, if you’re in the 90th percentile for forearm length, you should aim higher on forearm circumference as well.

Next, the size of your upper arms can affect how big your forearms look. If you have big biceps and triceps, you should also work on your forearms to prevent them from being disproportionately small.

Additionally, having smaller wrists can make your forearms appear larger when the muscles are well-developed. However, bigger wrist bones generally allow more potential forearm muscle and greater size.

Finally, having a higher body fat percentage or water weight can make your forearms larger, but ultimately they will look softer and more cylindrical. To create sweeping forearms, it’s best to have a lower body fat percentage and get rid of water retention.

How to Get Bigger Forearms

Building bigger forearms can be challenging because the flexor and extensor muscles are relatively small. In addition, they are used to getting worked as you hold and grip objects in your daily life. So they can be stubborn, like calf muscles.

Nevertheless, growing your forearms with an optimized workout and nutrition plan is possible.

Resistance Training

If you don’t lift weights, simply implementing a resistance training program can result in significant forearm growth. At first, you should notice forearm gains simply from gripping the bar during upper body exercises.

As you progress, however, you may require specific forearm training to get them to continue growing.

Forearm Exercises

You can directly train your forearms using exercises like wrist curls and reverse wrist curls, which target the flexor and extensor muscles. Additionally, specific bicep exercises like hammer curls and reverse curls are great for working the top of the forearm.