Use a soft measuring tape and keep it snug but not tight:

1. Neck
   Measure around the base of your pet’s neck where the collar or harness will sit. Leave about two fingers’ width of space for comfort.
2. Chest / Girth
   Measure the widest part of your pet’s chest, just behind the front legs.
   This is the most important measurement for harnesses.
3. Length (for coats or apparel)
   Measure from the base of your pet’s neck to the base of the tail