What size collar does my dog need?
Measure your dog's neck, then choose a collar whose adjustment range covers that number with room to spare. The dog collar size chart below gives typical sizes by weight and breed, but the tape measure decides.
Dog collar size chart by weight
| Size | Neck | Dog's weight | Example breeds |
|---|---|---|---|
| XXS | 6–8″ | up to 5 lb | Chihuahua, teacup Yorkshire Terrier |
| XS | 8–12″ | 5–10 lb | Maltese, Pomeranian, Toy Poodle, Yorkshire Terrier, miniature Dachshund |
| S | 10–14″ | 10–25 lb | Pug, Miniature Schnauzer, Cavalier King Charles Spaniel, Pekingese, Scottish Terrier |
| M | 14–20″ | up to 55 lb | Beagle, Border Collie, Boston Terrier, English Bulldog, French Bulldog |
| L | 16–26″ | up to 75 lb | Labrador Retriever, Golden Retriever, Boxer, Dalmatian, Weimaraner |
| XL | 24–30″ | over 75 lb | Great Dane, Mastiff, Rottweiler, Bernese Mountain Dog, Saint Bernard |
From PetSmart's dog collar size chart. Some sizes overlap: a dog with an 18″ neck could wear an M or an L. Pick the one where the measurement isn't at the very end of the range.
Collar and harness sizes from a second brand
Every brand sets its own ranges. Coastal Pet's chart, for example, puts a small collar at 10–16″ for dogs of 20–35 lb, where PetSmart's small is 10–14″ for 10–25 lb. Its harness sizes go by chest girth:
| Size | Dog's weight | Collar (neck) | Harness (chest) | Example breeds |
|---|---|---|---|---|
| XS | up to 15 lb | 8–12″ | 16–19″ | Dachshund, Shih Tzu, Yorkshire Terrier |
| S | 20–35 lb | 10–16″ | 19–23″ | Beagle, French Bulldog, Miniature Schnauzer |
| M | 30–50 lb | 14–20″ | 22–28″ | Australian Shepherd, Bulldog, Shetland Sheepdog |
| L | 50–80 lb | 18–26″ | 28–36″ | Boxer, German Shepherd, Labrador Retriever |
| XL | 90–150 lb | 20–28″ | 30–43″ | Great Dane, Mastiff, Rottweiler |
From Coastal Pet's sizing guide. Use these charts to narrow it down, then check your dog's measurements against the chart of the exact collar or harness you're buying.
How to measure your dog for a collar
- Use a soft tape. Wrap it around the neck where the collar will sit, which is fairly high on the neck, Coastal Pet notes. No tape? A piece of string marked and laid against a ruler works.
- Check it can't slip off. The AKC suggests seeing whether the loop could slide over your dog's head, tightening it until it couldn't, and noting that measurement.
- Match the range. Choose a collar whose adjustment range includes the measurement, ideally not right at the top or bottom. The checker above shows how much room is left each way.
- Do the finger test. With the collar on, two fingers should slide underneath. If they can't, it's too tight; if more fit, it's too loose.
Puppies outgrow collars fast. The AKC suggests an inexpensive nylon collar for a growing puppy, and Coastal Pet advises checking the fit regularly for puppies, young dogs and any dog that's gaining or losing weight.
Harness sizes and fit
Harness charts usually go by chest girth, sometimes with a neck measurement too. In the AKC's harness guide, veterinarian Amy Attas names the two places to measure: the base of the neck, where it meets the shoulders, and the widest part of the chest, usually just behind the front legs. Check both against one size on the maker's chart.
A harness should fit more snugly than a collar: you should have to squeeze two fingers under the straps, without it being uncomfortable. Then walk your dog to see that the legs move freely, tug in a few directions to check it won't slip off, and check again after grooming or a change in weight. Dogs with long or fluffy coats may need the straps a little tighter.
For crates, beds and litter boxes, see the pet gear size calculators and the dog crate size chart.
Questions owners ask
How do I know what size collar to get my dog?
Measure around your dog's neck with a soft tape, where the collar sits, then pick a collar whose listed range includes that measurement. The AKC advises going by the measurement rather than a small, medium or large label, because sizes differ between brands.
How tight should a dog collar be?
You should be able to slide two fingers under it, the AKC says. If you can't, it's too tight; if more fingers fit, it's too loose and could slip over the head.
What size collar does a Labrador need?
PetSmart lists Labrador Retrievers under its Large collar for 16–26″ necks, and Coastal Pet under its Large for 18–26″. Measure your own dog to see where it falls in the range.
Is collar size the same as neck size?
No. Neck size is your dog's measurement; collar size is the range a collar adjusts to. Coastal Pet's example: a dog with a 16″ neck might wear a collar that adjusts from 14 to 20 inches.
Should my dog wear a collar or a harness?
In the AKC's harness guide, a veterinarian recommends a harness for flat-faced breeds such as Bulldogs, French Bulldogs and Pugs, whose necks are almost as wide as their heads, and for older dogs, dogs that pull, and dogs with neck pain, breathing problems or heart disease.