How to properly determine your dog’s waist size:
To select the best size, measure your pet's waist to compare with the size chart.
To measure your dog, simply measure your dog’s waist in front of her back legs
Do this while they’re standing and use a cloth/flexible tape, if one is not available, use a piece of string or twine and then measure that with a ruler, or measuring tape.
Do not guess your dog’s size, always measure the waist for an accurate size. If your dog is at the very end of the range or in between ranges, factor in their weight, i.e: a heavier dog, go up a size, a skinner dog, go down a size.