Biceps. It doesn’t matter what car you drive. It only matters how big your arm is when it hangs out the window.
We all love having big biceps, but how do we stack up against the rest?
The average male has 13-inch biceps, while the average female is closer to 12.5 inches. However, we all have different biceps, and there are definite trends between gender, height, age, weight, and more.
Let’s delve into the different parts of the human race to see how we all differ according to bicep size.
What Are Biceps, Anyway?
Before we dive into what the differences are between all these people, we need to get a good understanding of what the biceps actually are. They’re more than just something to flex on Instagram, I’ll have you know.
The biceps actually consists of various different muscles, all working together – including the coracobrachialis, brachialis, and the biceps brachii.
By and large, the biceps have a few primary responsibilities, such as elbow flexion (curling the hand towards the shoulder), pronation and supination, and (somewhat) arm adduction.
Because all of these muscles work differently from one another and in different planes, it’s important to incorporate other bicep exercises in your routine for full bicep development.
But we aren’t here to talk about exercises or routines! We’re here to see the differences, why they appear, and if there are trends in the world of biceps.
First off, does your girl have bigger biceps than you?
Biceps Size by Gender
The first thing to remember is that bicep anatomy is identical between males and females.
Both sexes have all three parts of the bicep, and both have muscles (duh). Often, we hear females claiming they have “no muscle,” when in reality, they do have the muscle – just not in a large volume or size.
According to CDC statistics published in 2021, the average female bicep size is 12.5 inches. They also found that the largest biceps were found in women between the ages of 30 and 59. After age 59, bicep size decreases with age, most likely due to age-related atrophy of muscles.
That same analysis found that the average male bicep size is 13.5 inches, an 8% increase from the females – which makes 14-inch biceps about average. The largest biceps were found in men between the ages of 30 and 49.
So, why the increase in size from females to males?
Well, men have more testosterone compared to females and therefore have a greater ability to build larger muscles. Men are also typically larger than women.
One thing to note is that these stats come from the general population and don’t necessarily fit individuals or athletes.
Another thing to consider is that fat mass wasn’t taken into account. This means that while females in their 30s and 40s might have the largest biceps, this also seems like the age group most likely to carry extra fat tissue.
Biceps Size by Height
As a 6’ 4’’ guy myself, I can confirm that the taller you are, the harder it is to build muscle thickness.
That’s what we call anecdotal evidence! Just because I experience something, that doesn’t mean it’s true for everyone. We have to look at studies or scientific data to find truth or facts – our own personal observations don’t really matter.
There’s actually very little research on the correlation between height and bicep size. But for a long time, bicep size has been theorized as a means to measure the overall health of an individual. However, there are a few problems with this.
Generally, the taller the individual is, the smaller their biceps are. This is due to the fact that their weight is more “spread out” across a larger area. This means that the health argument can’t really be used since weight isn’t the best or only tool we have to determine health.
It’s not uncommon to see bicep size decrease incrementally as you go from a shorter height – like 5’ 4’’ to 6’ 4’’.
Biceps Size by Age
Aging is a natural process we all undergo, and despite the best efforts of medical engineers (and Sci-Fi movies), we still haven’t found a way to halt or slow the aging process.
When looking at bicep size and age, there are a few things you need to consider.
Firstly, humans tend to lose weight as we age, and most of this weight loss will come from losing muscle mass. This is due to a lack of exercise, changing dietary habits, and changing hormonal levels as well.
At the same time, most of us also tend to gain a bit of body fat during this period. Both of these are unhealthy in their own right, and the former is actually quite dangerous, as it increases the risk of injury quite dramatically.
Another thing to consider is that muscle loss and fat gain (due to aging) will happen at different rates for men and women. Women start with a lower amount of testosterone, to begin with, which makes it harder for them to build (and retain) muscle mass.
| Males | (Age vs Bicep Circumference, inches) | Females | (Age vs Bicep Circumference, inches) |
|---|---|---|---|
| 1 month – 1 year | 5.84 | 1 month – 1 year | 5.61 |
| 2 years – 4 years | 6.6 | 2 years – 4 years | 6.5 |
| 5 years – 7 years | 7.4 | 5 years – 7 years | 7.20 |
| 8 years – 10 years | 8.85 | 8 years – 10 years | 8.62 |
| 11 years – 13 years | 10.15 | 11 years – 13 years | 10 |
| 14 years – 16 years | 11.37 | 14 years – 16 years | 10.7 |
| 17 years – 19 years | 12.5 | 17 years – 19 years | 11.61 |
| 20 years – 22 years | 12.87 | 20 years – 22 years | 12.4 |
| 23 years – 25 years | 13.18 | 23 years – 25 years | 12.48 |
| 26 years – 28 years | 13.38 | 26 years – 28 years | 12.5 |
| 29 years – 31 years | 13.70 | 29 years – 31 years | 12.67 |
| 32 years – 34 years | 13.85 | 32 years – 34 years | 12.83 |
| 35 years – 37 years | 14.09 | 35 years – 37 years | 12.9 |
| 38 years – 40 years | 14.21 | 38 years – 40 years | 12.99 |
| 41 years – 43 years | 14.1 | 41 years – 43 years | 13.03 |
| 44 years – 46 years | 14.05 | 44 years – 46 years | 13.11 |
| 47 years – 49 years | 13.74 | 47 years – 49 years | 12.99 |
It would appear that age and bicep size works on a parabolic system. At younger ages, biceps appear to be larger, and around the late 40s, bicep size begins to decrease for both genders.
Bicep size loss is a percentage larger for men. That’s because they start off with a larger amount of muscle mass, to begin with.
Some ways to combat muscle loss as we age include training with resistance, a high-protein diet, hormone replacement, and a healthy lifestyle – in general.
This might be something you want to do, seeing as muscle loss (and fat gain) have been linked to various metabolic and cardiovascular diseases. Less muscle mass also makes you more susceptible to injuries.
We also experience a decrease in bone density due to aging, which, again, increases the risk of injury tremendously. One of the best ways to boost bone density and strength is weight training 3 – 4 times per week.
Besides weight and gender, age is one of the biggest influences on muscle mass, and thus bicep size.
Biceps Size by Weight
Weight is probably the factor that’ll determine bicep size the most (on this list). This also illustrates one of the biggest problems with measuring bicep size without taking weight into account.
Measuring bicep size without looking at body fat mass is not a great representation of health or general well-being.
We’ve all seen two large individuals – one being a mass monster that drinks protein shakes on dates, and the other is an obese person. Both of these individuals could have 20-inch biceps. However, an obese person suffers from high cholesterol, blood pressure, and blood sugar.
This is why weight shouldn’t be taken out of context. But most analyses done by data scientists don’t take muscle mass or fat mass into account. Just be aware that weight can be high or low based on muscle mass, fat mass, or even height.
| Males | (Weight, pounds vs Bicep Circumference, inches) | Females | (Weight, pounds vs Bicep Circumference, inches) |
|---|---|---|---|
| 10 – 50lbs | 5 – 8.5 | 10 – 50lbs | 5 – 8.35 |
| 50 – 75lbs | 8.5 – 10 | 50 – 75lbs | 8.35 – 9.6 |
| 75 – 100lbs | 10 – 10.15 | 75 – 100lbs | 9.6 – 10 |
| 100 – 125lbs | 10.15 – 10.8 | 100 – 125lbs | 10 – 10.5 |
| 125 – 150lbs | 10.8 – 11.37 | 125 – 150lbs | 10.5 – 10.9 |
| 150 – 175lbs | 11.37 – 12.2 | 150 – 175lbs | 10.9 – 11.4 |
| 175 – 200lbs | 12.2 – 12.7 | 175 – 200lbs | 11.4 – 12 |
| 200 – 225lbs | 12.7 – 13.2 | 200 – 225lbs | 12 – 12.7 |
| 225 – 250lbs | 13.2 – 13.8 | 225 – 250lbs | 12.7 – 13.2 |
| 250lbs + | 13.8 + | 250lbs + | 13.2 + |
As you can see, there’s a clear link between weight and bicep size for both genders. As weight increases, so does bicep size. This isn’t surprising, as both body fat mass and body muscle mass will cause an increase in body size.
Again, the problem remains that data scientists didn’t look at how much muscle mass vs. fat mass these individuals carry. Ideally, you’d want to look at a population and have different ranges of fat percentage per age/weight group.
This will allow you to see clearly how fat mass changes the reading of bicep size.
Biceps Size: A More General Overview
Bicep size has often been seen as a method to determine health or even gain more insight into the BMI readings of the general population.
The problem is that there’s a severe flaw in this. After all, this doesn’t take into account the amount of fat mass this person is carrying compared to muscle mass.
Generally, muscle mass is far healthier compared to fat mass. Two 300lb individuals could have exactly the same BMI, but one could only have 8% body fat, making them much healthier.
In general, there are a few things we can learn from looking at bicep measurements:
- Men have larger biceps than women at every age and at every weight. This is due to men having more muscle mass than women due to higher levels of endogenous testosterone (a muscle-building hormone).
- As weight increases, so does bicep size. This is most likely just due to the fact that mass takes up volume. There’s no way to determine how much of this mass is muscle and/or fat without more information being taken from the studied population.
- Both boys and girls gain a lot of sizes quickly in their teens, which is known as the growth spurt. Boys will still be larger than girls, and heavier kids will also tend to be larger as well.
That said, this is almost common knowledge, especially in the fitness world. It would’ve been nice to see a few studies looking at how fat mass and hormonal levels affect bicep size, especially as we age.
Looking at the biological differences between males and females would also have been ideal to see when female testosterone levels peak and if bicep size also peaks then.
Overall, the more you use something, the better (and bigger) it tends to get. Thus, those who train their biceps more will always have larger biceps, regardless of external factors.
