18 Inch Arms by Weight
Also, how much you weigh determines how big your arms look on your body. For example, 18 inch arms look much bigger on a 180-lb guy than a 250-lb guy.
In other words, the heavier you are, the bigger your arms must be to look impressive. Obviously, you want that weight to be muscle, not fat. I’ll get into that in a minute.
18 Inch Arms by Height
Finally, your height also affects how big your arms look.
To illustrate, picture a 5’6” person standing next to a 6’6” person. If they both have 18 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.
Arm Size Calculator
Height, weight, and age make it difficult to know if your arms are considered big. Fortunately, there are equations to predict average arm size based on these variables.
I created a simple calculator that shows you if your arms are big or small for your demographic.