The Graphics' industry standard is width by height (width x height). Meaning that when you write your measurements, you write them from your point of view, beginning with the width. That's important. When you give us instructions to create an 8×4 foot banner, we'll design a banner for you that is wide, not tall.

How do you write x width x height?

It needs to be written Length X Width X Height. That is standard for measurements. It makes no difference in the order you have them listed. The end result is the same.

What comes first in measurements?

The first dimension to measure is length. Length is always the longest side of the box that has a flap. The next dimension is width. The width side also has a flap, but is always the side shorter than the length.