Sizing:

X-Small: 7.5"-10" Length, 7.5"-9" Neck, 10.5"-13" Chest

Small: 9.5"-12" Length, 9"-11" Neck, 12.5"-16" Chest

Medium: 11.5"-14" Length, 10.5"-12.5" Neck, 15.5"-18" Chest

Large: 13.5"-16.5" Length, 12"-14" Neck, 17.5"-20.5" Chest

X-Large: 15.5"-18.5" Length, 13.5"-15.5" Neck, 20"-23" Chest

XX-Large: 17.5"-21" Length 15"-17.5" Neck, 22"-25.5" Chest

3X-Large: 21"-24.5" Length, 16.5"-20" Neck, 24.5"-29.5" Chest

4X-Large: 24.5"-28.5" Length, 19"-22.5" Neck, 28.5"-33" Chest

The following measurements are the dimensions of the actual product, not of the dog they fit. After measuring your pup, make sure all measurements fit within the following dimensions (with a little room to spare in the neck & chest).