Have a look at the chart below and select a set based on your dog's neck width, measured around where s/he wears a collar. There is some overlap between the sizes - when in doubt, select the smaller size if your dog has a smaller head and tends to slide out of collars; size up if your dog has a larger head and and could benefit from a wider collar.
All our leashes are 6' long - this is the most comfortable leash length for walking, hiking, and running with your dog for most people.
|Size||Leash size||Collar fits neck size...|
|S||5/8" wide and 6 feet long||10-14" (5/8" wide)|
|M||3/4" wide and 6 feet long||14-20" (3/4" wide)|
|L||1" wide and 6 feet long||18-26" (1" wide)|