How to measure Collar click in the right bottom corner of the image above to see a larger version of the image!
Collar sizes range form 20" - 28" and all my Collars are 1 1/4" wide.

If the Neck of your Dog measures for example 17" you should choose a Collar of the size 22". From the actual measurment of you Dog's Neck you should add 4" to maximum 5" depending on the age of your Dog, to be in the second hole of the 4 holes of the collar.

The only exception on my collars is the 20" collar it has only three holes!