XF 2.1 What is a good maxium size for an Avatar Pic

[DigNap15]

Hello
Many of my members are worried about their avatars taking up a lot of my bandwidth.
What is a good maximum size for a png or jpg original in pixels
I assume that Xenforo downsizes it.
So does the original size matter?

 

[SyTry]

Hello, I use 200 x 200, also 500 x 500 ^^