For a stand up pouch, it will have width, length, and bottom gusset to keep standing.
Most time we will measure the length from top to bottom and measure width from right to left, and measure the bottom gusset with folded gusset size. We called it outer size, this is standard measurement mode which most of our customers use.
As below picture shows.
If you only know the width and length of a stand up pouch, please don’t worry, we will give suitable size to match your bag size which can keep the bag stand very well when pack your product.