Extra Small:

• around the chest 7 inches behind the front legs (red color on the picture):
  16-20 inch (41-52 cm)
• minimum dog length: 12 inches (30 cm) from the base of the neck to the base of the tail.

Small:

• around the chest 7 inches behind the front legs (red color on the picture):
  23-32 inch (58-81 cm)
• minimum dog length: 16 inches (41 cm) from the base of the neck to the base of the tail.

Medium:

• around the chest 7 inches behind the front legs (red color on the picture):
  24-33 inch (60-84 cm)
• minimum dog length: 21 inches (54 cm) from the base of the neck to the base of the tail.

Large:

• around the chest 7 inches behind the front legs (red color on the picture):
  27-37 inch (69-95 cm)
• minimum dog length: 26 inches (63 cm) from the base of the neck to the base of the tail.

Extra Large:

• around the chest 7 inches behind the front legs (red color on the picture):
  36-47 inch (90-120 cm)
• minimum dog length: 28 inches (71 cm) from the base of the neck to the base of the tail.