Pet Parents HQ

Dog Collar Size Chart

Dog collar sizes by breed and weight, how to measure a neck properly, and the two-finger rule that decides whether a collar is safe or a hazard.

Collar size chart by weight

Dog weightNeck sizeCollar sizeWidth
Under 10 lb8–12″XS⅜–½″
10–25 lb10–14″S½–¾″
25–55 lb14–18″M¾–1″
55–75 lb16–22″L1–1½″
75–100 lb20–26″XL1½–2″
100 lb+24–30″XXL2″

Typical neck sizes by breed

BreedNeck circumferenceCollar size
Chihuahua8–12″XS
Yorkshire Terrier8–12″XS
Dachshund10–14″S
French Bulldog12–16″S–M
Beagle13–17″M
Border Collie14–18″M
Labrador Retriever18–24″L
German Shepherd18–26″L–XL
Rottweiler20–28″XL
Great Dane22–30″XL–XXL

Individual dogs vary — always measure rather than ordering on breed alone.

How to measure correctly

  1. Have your dog stand normally, head up.
  2. Wrap a soft tape (or string) around the middle of the neck, where a collar naturally rests — not right up behind the ears, not down at the shoulders.
  3. Keep the tape snug but not tight against the fur.
  4. Add about 2 inches for small dogs, 3 inches for large, so two fingers fit underneath.
  5. Choose a collar whose adjustable range puts your measurement in the middle, not at either extreme.

Getting the fit right

  • The two-finger rule: two fingers flat, slid between collar and neck. That's the whole test.
  • Sighthounds need martingales. Greyhounds, whippets and similar have heads narrower than their necks and can reverse straight out of a flat collar.
  • Check puppies weekly — they outgrow collars faster than owners expect. Predict where they're heading with the puppy weight calculator.
  • Long-coated breeds may need re-checking after grooming; a collar fitted over a thick winter coat is too loose once it's clipped.
  • Remove collars in crates — tags and buckles catch on bars. If you need sizing for the crate itself, the dog crate size calculator covers it.

Frequently asked questions

How do I measure my dog for a collar?+

Wrap a soft tape measure around the middle of your dog’s neck, where the collar naturally sits, and add two fingers’ width of slack. If you do not have a tape, use string and measure it against a ruler afterwards.

How tight should a dog collar be?+

The two-finger rule: you should be able to slide two fingers flat between the collar and your dog’s neck. Tighter risks chafing and breathing problems; looser and a determined dog can back out of it — the most common way dogs get loose on walks.

What width collar does my dog need?+

Match width to size: ⅜–½ inch for toy breeds, ¾ inch for small to medium dogs, 1 inch for medium to large, and 1½–2 inches for large and giant breeds. Wider collars spread pressure and last longer, but look bulky on small necks.

How often should I check a puppy’s collar?+

Weekly. Puppies outgrow collars alarmingly fast, and a collar that fitted last month can be genuinely tight this month. Check the two-finger rule every week until they finish growing.

Should my dog wear a collar all the time?+

For ID purposes many owners do, but remove collars for crating and unsupervised play — collars can catch on crate bars, furniture and other dogs’ jaws. Breakaway safety collars exist for exactly this reason.

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