Sizing Size Chest Width Girth Measurement Weight Petite 6"-7" 12"-16" Under 10 lbs. Petite / Small 8"-9" 13"-18" 10-15 lbs Small 8.5"-11" 15"-21" 15-25 lbs. Small / Medium 11"-13" 19"-26" 20-30 lbs. Medium 12"-15" 21"-32" 25-50 lbs. Medium / Large 14"-18" 24.5"-34" 40-65 lbs. Large 16"-21" 27"-40" 65-95 lbs. Extra Large 17.5"-23.5" 32"-50" 90+ lbs.
