Average Arm Size & What Is Considered Big
Written By: Jeremy Fox, BSEng, CNC, CPT – Published: January 29, 2024
Have you ever wondered if your arms are bigger or smaller than average? Generally speaking, the average flexed arm size is 14.6 inches (37.1 cm) for men and 13.4 inches (34.0 cm) for women.
However, the normal arm size can vary depending on age, height, weight, and body composition. So, in this article, I will share actual arm size statistics for men and women of different ages relative to body size.
Data Collection Methods – the arm size information in this article was collected from the CDC’s anthropometric reference data for children and adults in the United States. Since these measurements were taken with arms relaxed, I also created a “flex multiplier” to adjust the data to typical bodybuilding measurements. I also developed a predicted arm size calculator based on data from a NHANES survey.
What Is Arm Size?
Big arms are often seen as a symbol of physical fitness and strength. This is why arm curls are one of the most popular exercises at the gym. However, it can be challenging to determine if your arms are average or above average.
Upper arm circumference is a common way to measure arm size and track progress. Arm circumference is measured around the largest part of the upper arm, usually the widest part of the bicep and tricep.
How to Measure Your Arms
Measuring your arm accurately is essential to determine how your arms compare to the average. You can use a flexible tape, like a tailor’s tape, to do so.
Start by raising one arm parallel to the floor and placing the end of the tape with the number “1” over the front of your bicep. Then, wrap the other end of the tape around the widest part of your arm until the numbers overlap the end.
The number where the tape intersects with the end is your arm size. Remember that bodybuilders may measure their arms flexed, as shown in the image below.
Tips: Do not pull the tape too tight or your arm will appear smaller. Also do not wrap the tape at an angle or your arm will appear bigger.
Average Arm Size Statistics
Now that you know how to measure your arms, I will provide additional data so you can see how your measurement compares to other people in your demographic.
Average Arm Size by Age & Gender
As we age, our arm size is influenced by various factors. During childhood, we all start with skinny arms, but as we grow through our teenage years, our arms also grow.
Once we reach adulthood, arm growth slows down. However, most people tend to experience a slight increase in arm size during their 20s and 30s.
As we enter our 40s, our arms might gradually start to decrease in size. This decline can be attributed to the drop in hormones and decreased physical activity.
Table 1. Average Arm Size By Age For Men & Women (Unflexed)
| Age | Men | Women |
|---|---|---|
| 20-29 | 13.4 inches (34.1 cm) | 12.4 inches (31.5 cm) |
| 30-39 | 14.1 inches (35.9 cm) | 12.9 inches (32.8 cm) |
| 40-49 | 14.0 inches (35.6 cm) | 13.1 inches (33.3 cm) |
| 50-59 | 13.7 inches (34.8 cm) | 12.9 inches (32.8 cm) |
| 60-69 | 13.5 inches (34.4 cm) | 12.8 inches (32.4 cm) |
| 70-79 | 13.1 inches (33.2 cm) | 12.6 inches (32 cm) |
| 80+ | 12.1 inches (30.8 cm) | 11.7 inches (29.6 cm) |
This data is from the US National Center for Health Statistics. However, the measurements are taken with the arm relaxed or unflexed.
Arm Size Flexed vs. Unflexed
When you flex your bicep, your arm increases in size by approximately 5-10%. This means that if your arm measures 13.5 inches when it is unflexed, it will typically measure around 14.5 inches when it is flexed.
Therefore, adjusting the data from the previous table is essential to ensure a fair comparison. Below is the revised arm size data, which takes into account the estimated increase in size when the bicep is flexed.
Table 2. Average Arm Size By Age For Men & Women (Flexed)
| Age | Men | Women |
|---|---|---|
| 20-29 | 14.4 inches (36.6 cm) | 13.3 inches (33.7 cm) |
| 30-39 | 15.2 inches (38.6 cm) | 13.9 inches (35.3 cm) |
| 40-49 | 15.1 inches (38.4 cm) | 14.1 inches (35.8 cm) |
| 50-59 | 14.7 inches (37.3 cm) | 13.9 inches (35.3 cm) |
| 60-69 | 14.6 inches (37.1 cm) | 13.7 inches (34.8 cm) |
| 70-79 | 14.1 inches (35.8 cm) | 13.5 inches (34.3 cm) |
| 80+ | 13 inches (33 cm) | 12.5 inches (31.8 cm) |
In Table 2, you can see that the average man has around 14½ inch arms. For women, the average arm size is a little smaller at 13½ inches.
To put this arm size data in perspective, it helps to look at it in terms of percentiles. This shows you how likely you are to have arms of a certain size.
The 50th percentile represents the average arm size. By comparison, a lower percentile is considered small, and a higher percentile is considered big.
Table 3. Arm Size Percentiles For Men & Women (Flexed)
| Percentile | Men | Women |
|---|---|---|
| 5th | 11.9 inches (30.3 cm) | 10.5 inches (26.8 cm) |
| 10th | 12.6 inches (31.9 cm) | 11.1 inches (28.1 cm) |
| 15th | 12.9 inches (32.8 cm) | 11.4 inches (28.9 cm) |
| 25th | 13.4 inches (34.1 cm) | 12 inches (30.6 cm) |
| 50th | 14.6 inches (37.1cm) | 13.4 inches (34.1 cm) |
| 75th | 16 inches (40.7cm) | 15.2 inches (38.5 cm) |
| 85th | 16.9 inches (42.9 cm) | 16.2 inches (41.2 cm) |
| 90th | 17.4 inches (44.2 cm) | 17.2 inches (43.7 cm) |
| 95th | 18.4 inches (46.7 cm) | 18.2 inches (46.1 cm) |
Now you can see the likelihood of having a certain arm size based on your gender. But you probably aren’t having a flex off with an 80-year-old.
So here are some charts to help you visualize how big certain arm sizes are based on a normal distribution of arm sizes for people ages 20-59.
Average Arm Size by Height
It’s also important to understand that height affects how big your arms look. To illustrate, picture a 5’6″ person standing next to a 6’6″ person.
If they both have 15-inch arms, the short guy’s arms will look much larger. So, the taller you are, the bigger your arms must be to look impressive.
Average Arm Size by Weight
Finally, how much you weigh also determines how big your arms look on your body. For example, 16-inch arms look much more prominent on a 150-lb guy than on a 250-lb guy.
In other words, the heavier you are, the bigger your arms need to be to look impressive. Obviously, you want that weight to be muscle, not fat. I’ll get into that in a minute.
Average Arm Size Calculator
Determining if your arms are considered big based on your height, weight, and age can be challenging. However, mathematical equations can predict the average arm size according to these factors.
To make it easier, I have designed a straightforward calculator that determines whether your arms are big or small for your demographic.
Arm Size & Body Fat Percentage
A few other factors can affect the size of your arms, which are not included in the arms size equation. One such factor is your body fat percentage.
Your arms will appear larger if you have more muscle and less fat. This is because you can see the separations between your arm and shoulder, and sometimes even the muscle striations and veins. Additionally, being leaner makes your arms look bigger compared to your arm joints (wrist, elbow) and your waist.
To illustrate this, here’s an example of what I look like when bulking versus cutting. In both pictures, my arms have a circumference of about 16 inches. However, they look bigger when I’m lean!
I weighed 198lbs on the left and 171lbs on the right and I’m 5’9″ tall. It goes to show that 16″ arms look bigger when you’re lean. I should also note that I had an arm pump in both pictures.
Arm Size Pump vs. No Pump
It is essential to understand that increased blood flow to your arms during a workout can cause them to swell up – commonly known as “the pump.” Therefore, measuring your arms immediately after an arm workout can add 0.5-1 inch to their size.
For accurate measurements, it is recommended to measure your arms when they are not pumped up. This way, you can determine your actual arm size rather than just the temporary volume gained from curls and pressdowns.
However, measuring your arms after a vigorous workout can be fun to see how big you can get them. Just remember that the inflated measurement does not accurately represent your arms’ typical size. Take it with a grain of salt and enjoy the temporary boost in size.
A juicy pump temporarily increases the size of your arms. In this picture, I am using blood flow restriction training to maximize muscle cell volume.
How to Get Bigger Arms
Developing bigger and stronger arms requires a well-rounded approach, including a balanced diet, targeted workouts, and effective supplements.
Diet
It may come as a surprise, but how you eat is just as important as working out when building muscle. You won’t see much progress in the gym without providing your body with the necessary nutrients.
To gain muscle consistently, you need to create a calorie surplus. This means that you should consume more calories than you burn each day.
Next, you must eat enough protein to give your arms the building blocks to grow new muscle tissue. And don’t listen to that 1 gram of protein per pound of body weight bro science!
Your lean mass, activity level, and fitness goal dictate how much protein you need.
Calculate Your Grams of Protein Per Day
Some other nutrition advice I have is to eat mostly clean foods. Skip the junk and steer towards whole, natural foods to get the most quality gains.
Also, tap into nutrient timing to unlock the last 10% of potential arm gains. That means getting most of your carbs and calories around your workout.
Custom Meal Plan
Get a personalized meal plan designed specifically for your body and lifestyle. Including custom recipes formulated to fit your macros and calories – no counting required!
All this for just $13.99/mo! Click here to choose your plan.
Workouts
To build big arms, you need to train your whole body. That may sound counterintuitive, but compound exercises like squats and deadlifts boost muscle-building hormones that help you build big arms.
As for your biceps, they are made up of an inner and outer head. The inner head creates size and thickness, while the outer head adds to the peak. So include a variety of exercises to hit both bicep heads.
Hammer Curls vs Bicep Curls For Peak & Width
Also, don’t forget to train your triceps because they make up approximately 2/3 of the area of your arm! Therefore, big triceps make it easier to build sizable arms.
Supplements
It’s important to keep in mind that taking supplements won’t work miracles on your arms in just a few days or weeks. Supplements should be considered as a complementary addition to a proper diet and exercise routine, which may provide a slight advantage.
Moreover, many costly supplements are ineffective and a waste of money. However, here are some reliable muscle-building supplements that have been proven to help increase the size of your arms.
How To Build Your Arms Faster
Now you know how your arms measure up. And you’ve learned some quick tips for building bigger arms.
If you want to grow your arms in weeks instead of months, start with a dialed-in muscle gain meal plan. And you can get a personalized, easy-to-follow nutrition plan right here.
Click the image or button below to learn more about Custom Meal Plans for Muscle Growth.
More Body Measurements
If you enjoyed this article, you’re probably curious about average measurements for other body parts. So here is a list of some additional articles about body measurements and proportions.
Average Waist Size for Men & Women
Relative Size of 20 Inch Thighs by Gender
Average Wrist Size & Why It Matters
Normal Forearm Size & How to Grow Them
Or if you’re all measured out, feel free to check out some of my other helpful content below! You’ll find information on topics ranging from supplements and workouts to bodybuilder bios.
See the average butt size for men and women based on age and race with tables and charts. And how to increase your butt size naturally.
When buying protein there are a lot of confusing terms like isolate and concentrate. Learn what these terms mean & which is better for weight loss & muscle gain.
See how long it takes to build muscle based on your experience level and fitness goal. Then get tips to optimize your rate of muscle gain!
Learn the fundamentals of bodybuilding nutrition for fat loss and muscle gain with this simple four part framework.
Learn about the most effective dosage and timing to maximize your gains with this complete guide on how to take creatine.
The Smith machine split squat is a versatile exercise that you can adjust to hit specific parts of your legs with simple foot placement.
A 29-inch waist can be healthy, according to medical professionals, but it actually depends on your gender and body type!
References
1) Fryar, Cheryl D., Qiuping Gu, and Cynthia L. Ogden. “Anthropometric reference data for children and adults; United States, 2015-2018.” (2021).
2) Ostchega, Yechiam, et al. “Estimating equations and tables for adult mid-arm circumference based on measured height and weight: data from the third National Health and Nutrition Examination Survey (NHANES III) and NHANES 1999–2000.” Blood pressure monitoring 9.3 (2004): 123-131.
