You need these measurements for the booties. Start by measuring front paws, because they usually are slightly bigger than back paws.
To make sure the position is right, place your dogs paw on a paper at the floor and draw paws outline to the paper.
Before drawing make sure that dog stands with whole weight at the paper.
Measure your drawings and compare to the bootie measures.
If the size is between two sizes prefer ordering the slightly bigger one than too small bootie. Material might rib, if the bootie is too small or abrade the paws.
A) Paw width: Measure at the widest point of the pads. B) Paw lenght: Measure behind the pads all the way to the nails. (Tip: remember to keep nails short enough, to prevent booties from ribbing) C) Paw circuit: Make a hoop of your measuring tape and string it trough paw. Measure circuit from the widest and highest points.