good size of arms? bicep

for a 15 year old wats a good size? not like super built but just like a good enough size. also is i tnormal if some days i wake up with my arms feeling buff but others they dont?

How tall are you?  What do you weigh? 
 
If you are 5'6" and you have 16" arms, that's pretty good.  I'm 5' 4.5" and have almost 17" arms.
 
If you are 6' 2" and have 15" arms, you could do better. 
 
See?

im 5'4 (wish i could get taller) and about 130, im trying to eat more

wait i mean 120 lbs

A. Well it all depends on your height really, not your age group.
B. Yes, it's normal, that'd have to do with general bloodflow or the workout you had the previous day.

- 6'2 with 16" arms is still pretty damn good.
- My arms look huge in tanktops and they're 14-15" (I'm 5'5")

And if you eat healthy and get your vitamins then you'll get those growth spurts you missed out on. Although at 5'5" I'm damn happy with my height.

It's good to take pride in your physical qualities.

Just bulk up. Don't stress about arm size.

i had 15" when i was 15 yo. i got 16's now just hit that mark and im 5'10". if you gain weight, your arms will go up for me its about 11 pounds to an inch normally. 

5'10" 181 lbs. max bench 285 lbs. 240x8 max squat: 375 lbs. 305x10 bf: around 10

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