Actual effective resolution and ratio for custom banners?

[The Order of Makai]

Hello, I've been going slowly mad trying to figure out the exact ratios for custom banners to be displayed in full without any cropping of the image once its been uploaded.
I am asking this mainly because whatever the true ratio is, it certainly is not 4 to 1 and 1200 x 300 as has been repeatedly claimed, because even then the darn thing still loses at least 100 pixels off the top and bottom, which for the banners I want to use typically means the loss of eyes and the majority of a head.

I understand that not every monitor set-up displays it the same way, but lets just assume that the average user is using a 16:9 monitor and viewing the website with a maximized web browser. So what is the actual effective resolution and ratio so that I can avoid cutoff and centering of my custom banner?

[Phydios]

Hello, I've been going slowly mad trying to figure out the exact ratios for custom banners to be displayed in full without any cropping of the image once its been uploaded.
I am asking this mainly because whatever the true ratio is, it certainly is not 4 to 1 and 1200 x 300 as has been repeatedly claimed, because even then the darn thing still loses at least 100 pixels off the top and bottom, which for the banners I want to use typically means the loss of eyes and the majority of a head.

I understand that not every monitor set-up displays it the same way, but lets just assume that the average user is using a 16:9 monitor and viewing the website with a maximized web browser. So what is the actual effective resolution and ratio so that I can avoid cutoff and centering of my custom banner?

Screen resolution matters too, not just width:height ratio. Players could be using 1366x768, 1920x1080, or some other resolution that is 16:9. Plus, some laptops are doing 16:10 ratios, which is a subtle but important difference. I think that is why the admins can't guarantee the portion of your banner that a player will see.