Yellow Dog Design Sizing Guide:

The adjustable length shown is the distance around the collar from the minimum to maximum adjustment.

Standard Collar:

Size Width Adjustable Length
Teacup 3/8" 4" to 9"
XSmall 3/8" 8" to 12"
Small 3/4" 10" to 14"
Medium 3/4" 14" to 20"
Large 1" 18" to 28"

Martingale Collar:

Size Width Adjustable Length
XSmall 3/8" 10"
Small 3/4" 14"
Medium 1" 20"
Large 1" 26"

Step- In Harness:

Size Width Adjustable Length
XSmall 3/8" 4 1/2" to 9"
Small 3/4" 9" to 15"
Medium 3/4" 15" to 25"
Large 1" 25" to 40"
XLarge 1" 40" to 55"

Harness:

Size Width Adjustable Length
XSmall 3/8" 8" to 14"
Small/Medium 3/4" 14" to 20"
Large 1" 20" to 28"
XLarge 1" 28" to 36"

If you are not sure, please call us at 877-800-8181 to speak to a customer service representative.