Forearms are one of the most underrated muscles in the body. They’re always on display, play a central role in grip strength, and are essential for balance in arm aesthetics.
Yet when people ask, “What’s the average forearm size?” the answers online are often vague.
This article explains average forearm circumference, differences between men and women, how to measure properly, what studies say, and how to build forearms that stand out.
Related: Average Grip Strength by Age
What Is the Average Forearm Size?
Anthropometric studies, research measuring body dimensions, give us benchmarks:
- A large dataset from the U.S. Army Anthropometric Survey (ANSUR, 1988) shows the average male forearm circumference is around 11.5–12.5 inches (29–32 cm).
- For women, average measurements fall around 9.5–10.5 inches (24–27 cm).
These numbers represent the general population, not athletes. In fitness circles, muscular forearms often measure much larger:
- Athletic men: 13–15 inches.
- Athletic women: 11–12.5 inches.
So, if you’re hitting the gym regularly, your target should go beyond the general averages.
How to Measure Forearm Circumference Correctly
Getting an accurate reading matters. Here’s the step-by-step:
- Use a soft measuring tape (tailor’s tape).
- Position your arm straight but relaxed.
- Measure at the largest part of the forearm, typically 1/3 of the way down from the elbow toward the wrist.
- Keep the tape snug but not tight.
- Record in inches and centimeters for comparison.
Repeat the measurement a few times to get a consistent number.
Average Forearm Size by Gender and Height
Forearm size isn’t one-size-fits-all. Taller, heavier people usually have naturally thicker forearms.
- Men under 5’7” often fall in the 10.5–11.5 inch range.
- Men 5’10”+ typically measure 12–13 inches on average.
- Women 5’3” and under average around 9–9.5 inches.
- Women 5’7”+ average closer to 10–11 inches.
A 2017 anthropometric analysis confirmed that forearm circumference strongly correlates with body height and weight (Norton et al., Journal of Bodywork and Movement Therapies).
Forearm to Bicep Ratio | The Aesthetic Benchmark
While averages tell you what’s “normal,” aesthetics depend on proportions. Bodybuilding wisdom suggests:
- Forearm to bicep ratio should be around 70–80%.
Example:
- 16-inch bicep → 11.5–12.5 inch forearm looks balanced.
- 14-inch bicep → 10–11 inch forearm keeps proportions natural.
If your forearms are much smaller than this ratio, your arms may look top-heavy.
Why Forearm Size Matters Beyond Looks
Strong, developed forearms are more than a visual detail. Research highlights their importance:
- Grip strength and health: A 2015 study in The Lancet linked grip strength (a direct product of forearm strength) with reduced risk of cardiovascular disease and mortality. Strong forearms = better overall health marker.
- Sports performance: Baseball, tennis, climbing, and martial arts rely heavily on forearm endurance and power.
- Weightlifting success: Deadlifts, pull-ups, and rows all depend on grip. Weak forearms often mean stalled lifts.
In short, average is fine for health, but stronger and thicker forearms give you both performance and aesthetics.
How to Grow Bigger Forearms
If your measurements fall below average, or your biceps overshadow your lower arms, forearm-focused training is the answer.
Here are some of the best ways to grow your arm:
Best Forearm-Building Exercises
- Wrist curls (palms up and down) – Target flexors and extensors.
- Hammer curls – Add overall thickness.
- Reverse curls – Build balanced strength.
- Farmer’s carries – Develop raw grip strength and size.
- Dead hangs – Stretch and strengthen under load.
- Gripper training – Directly isolate forearm and grip muscles.
This is where tools make all the difference:
- The Gripzilla Hand Grippers let you progressively overload your grip just like a barbell does for your chest.
By working through resistance levels, you force your forearm muscles to adapt and grow thicker.
- The Gripzilla Tornado (a dynamic wrist and forearm trainer) takes things further by hitting your stabilizers with rotational resistance.
It mimics the stress your forearms face in sports, climbing, and heavy lifts, accelerating strength and size gains.
Genetics vs Training: Do Forearms Grow Easily?
Forearm growth varies dramatically:
- People with naturally thick wrists usually have a head start.
- Those with thinner bone structure often find forearms harder to grow.
Still, consistent progressive overload, especially through grip-intensive training, can push past genetics. A 2018 study in Journal of Strength and Conditioning Research confirmed that direct grip training increases forearm circumference significantly within 12 weeks.
Average Forearm Size FAQ
What’s considered big forearms?
Over 13 inches for men and 11 inches for women is generally considered muscular.
Do small wrists mean I’ll never have big forearms?
Not at all. Small wrists mean a smaller frame, but muscle growth is still achievable.
Can forearm training improve grip quickly?
Yes, within 8–12 weeks, grip and forearm size improve measurably with consistent training.
Final Thoughts
The average forearm size ranges around 11.5–12.5 inches for men and 9.5–10.5 inches for women.
But averages don’t tell the whole story. Balance, aesthetics, strength, and health all come into play.
If you want forearms that stand out:
- Measure correctly.
- Compare your ratio to your biceps.
- Train with direct forearm work 3–4 times a week.
Strong, developed forearms aren’t just about looks, they’re a marker of strength and overall fitness.
