How to Size a Dog Collar

"Take the bell off my collar so I can hide."
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Incorrectly sized dog collars can cause your pet pain if too tight, slip off if too loose or break if they are too thin. Dog collars are functional as an item to carry dog identification and to use for walking on leash and for training purposes. There are an incredible number of styles and colors to choose from when dressing your dog up for a romp at the park. Sizing his new collar correctly allows him to be stylish and comfortable at the same time.

Step 1

Measure your dog’s neck size with a cloth measuring tape. If you do not have this type of measuring tape, wrap a string around his neck and cut it to his neck size. Lay the piece of string next to a yardstick, ruler or metal measuring tape and record the neck size.

Step 2

Add 1 inch to your furry friend’s neck size if he is a small breed under 10 pounds. Add 2 inches to the measurement if he is a medium-sized dog and 3 inches for large-breed dogs that are more than 80 pounds. The measurement plus the additional inch or inches is his collar size.

Step 3

Measure a long-haired dog that receives haircuts right after a trip to the groomer with his hair short. Re-measure your dog when his hair is longer just before another haircut. This will give you a range in his neck size to accommodate both long and short hair. Choose a dog collar that is adjustable to fit both neck sizes.

Step 4

Determine the collar’s width you need by the size of your dog and his strength. Toy and small breeds do not pull as hard as larger breeds and only require a thin collar. Large breeds with a lot of power need a thicker collar to hold up under their stress. It's possible to get a collar in either of two widths that are the same length. If your dog is rambunctious and he falls into this category, choose the wider width.

Step 5

Purchase a dog collar for a growing dog in an adjustable style. His current neck size should be on the smaller end of the adjustment scale. This allows the collar to grow with your dog so you will purchase fewer collars in the growth stage and only one at his adult age.

Step 6

Place your dog’s new collar on his neck and snap or buckle it. Move the adjustment slide on an adjustable model so you can place one finger between the collar and his neck from small breeds, two fingers for medium breeds and three fingers for large breeds.


  • Don’t measure an old collar for the appropriate length you need. Old leather collars can stretch and add additional inches to their length.

  • Ill-fitting dog collars can come off over your dog’s head if they are too large or can rub the fur off his neck and lead to skin infections if they are too tight.


  • Examine your dog’s collar at least monthly for stretching, fraying or tears. Replace his collar if it is defective in any manner. This will protect him from breaking it during a walk and running to chase a cat or other critter.

  • Check growing dogs' collars monthly and lengthen as needed to remain a comfortable length.

  • Adjustable collars may enlarge from 3 to 6 inches, dependant on the brand.

  • Wider width collars for large breeds are also thicker and have more sturdy hardware to curb your pet effectively.

Items You Will Need

  • Cloth measuring tape
  • String (optional)
  • Yardstick (optional)