What are average advertising banner widths?

Question

Many websites have advertising, do people know what the general/average/standard width of advertising areas and banner widths are?

Thanks in advance

Answer 1

Google's banners are probably a good standard to start from.

Answer 2

You can find the most common standard sizes here: Wikipedia: Web banner

As the height is easier to vary than the width in a layout, you will often find advertisers using variations where a standard width is chosen, like for example 250, and different heights are combined with that, like 250x125, 250x250, 250x375.

Answer 3

You can find the most common standard sizes here: Wikipedia: Web banner