How to Measure Your Dog for a Collar or Harness (Size Chart by Breed)

To measure your dog for a collar, wrap a soft tape measure around the neck where the collar naturally sits, which is a few centimetres below the ears and above the shoulders. Read the number, then add 2 to 3 cm for comfort. Check the fit with the two finger rule: you should be able to slide two fingers flat between the collar and the neck, no more and no less. If your dog falls between two sizes, size up. Below is the full method, a dog collar size chart by breed, how to measure for a harness, and the four mistakes that cause most returns.

In this article

• What you need
• How do I measure my dog's neck in 3 steps?
• What size collar does my dog need?
• How do I measure my dog for a harness?
• What size collar does a puppy need?
• 4 mistakes that cause a bad fit
• FAQ

What you need

• A soft tape measure, the kind used for sewing.
• No tape measure? Use a piece of string or a phone charging cable, mark the overlap point with your thumb, then hold it against a ruler.
• A calm dog. Measure after a walk, not before one.

How do I measure my dog's neck in 3 steps?

Step 1: Find where the collar actually sits

Not at the very top of the neck under the jaw, and not down at the shoulders. The right spot is the middle of the neck, roughly two to three finger widths below the ears. On a dog with a thick ruff, part the coat with your fingers first so you are measuring the neck and not the fur.

Step 2: Wrap and read

Bring the tape around and let it sit flat against the coat without compressing it. Snug, not tight. Write the number down in centimetres or inches, whichever the shop you are buying from uses, and do not convert in your head at checkout.

Step 3: Add the comfort allowance, then check with two fingers

Add 2 to 3 cm, or about 1 inch, to your measurement. That allowance is what makes the difference between a collar that fits and a collar that chafes. Once the collar is on, slide two fingers flat between the collar and the neck. Two fingers with slight resistance is correct. One finger is too tight. Four fingers means your dog can back out of it, which is the exact scenario a collar exists to prevent. The American Kennel Club uses the same two finger check.

What size collar does my dog need? Dog collar size chart by breed

Use this dog collar size chart as a starting point, not as a substitute for measuring. Neck size varies enormously inside a breed, and a well muscled Labrador and a slim one can be two sizes apart. The sizes below match our Evergreen walk sets.

Size	Neck circumference	Typical breeds
XS	20 to 30 cm (8 to 12 in)	Chihuahua, Toy Poodle, Yorkshire Terrier, small Dachshund
S	28 to 38 cm (11 to 15 in)	Standard Dachshund, Pug, Jack Russell, Shih Tzu
M	35 to 45 cm (14 to 18 in)	French Bulldog, Beagle, Cocker Spaniel, Border Collie
L	42 to 52 cm (17 to 20 in)	Labrador, Golden Retriever, Boxer, Australian Shepherd
XL	48 to 60 cm (19 to 24 in)	Bernese Mountain Dog, German Shepherd, Rottweiler, Great Dane

Two breed notes worth knowing. Dachshunds have long, comparatively slim necks, so if yours measures between XS and S, start with XS. French Bulldogs and Pugs have necks that are close to the width of their heads, so a collar that fits the neck can still slip off over the head. For those breeds a well fitted harness is often the better everyday choice.

How do I measure my dog for a harness?

A harness needs a different number than a collar. The measurement that decides the size is the chest girth: the widest part of the rib cage, just behind the front legs.

1. Measure the chest. Wrap the tape around the rib cage directly behind the front legs, flat against the coat. This is the number most harness size charts are built on.
2. Measure the neck base. Some harnesses also list a neck range. Measure lower than for a collar, where the neck meets the shoulders.
3. Add room and check. Add 2 to 5 cm to the chest measurement, depending on how fluffy the coat is. Once the harness is on, two fingers should slide under every strap, and the harness should not shift sideways when the dog pulls.

For flat faced breeds such as French Bulldogs and Pugs, a harness that takes pressure off the throat is kinder on the airway. Measure after a meal rather than on an empty stomach, because that is how the dog will be wearing it most of the time. Our Cloud 7 harnesses ship from our Swiss stock and are currently available in Switzerland and Europe.

What size collar does a puppy need?

Puppies outgrow collars fast, and a growing dog is the one situation where buying to last is a mistake. Buy an inexpensive adjustable collar now, remeasure every four to six weeks until roughly 12 months, and only then buy the collar you actually want. If you are gifting a walk set to a puppy household, choose the most adjustable size that fits today, because a collar with a wide adjustment range buys you a few extra months while the puppy grows into it.

4 mistakes that cause a bad fit

1. Measuring over thick fur. On a double coated breed the measurement can come out 3 to 4 cm too large. Part the coat first.
2. Measuring in the wrong place. High up under the jaw gives a number that is far too small. Measure where the collar will actually sit.
3. Buying tight so it "does not slip". A tight collar rubs and can restrict breathing. A collar that stays on is one that fits with two fingers of room, not one that is cinched down.
4. Never checking again. Weight changes, seasonal coat changes and a puppy's growth all change the fit. Recheck the two finger test every few months, and after a grooming appointment.

Frequently asked questions

How do I measure my dog's neck for a collar?

Wrap a soft tape measure around the middle of the neck where the collar sits, keep it flat and snug without compressing the coat, then add 2 to 3 cm. Confirm with the two finger rule once the collar is on.

How tight should a dog collar be?

Tight enough that it will not slip over the head, loose enough that two fingers slide flat underneath with slight resistance. If you can only fit one finger, go a size up.

What size collar does my dog need if it is between two sizes?

Size up in almost every case, since most collars adjust downward but not upward. The exception is a slim necked breed such as a Dachshund, where starting at the smaller size often fits better.

Can I measure my dog without a tape measure?

Yes. Wrap a piece of string or a charging cable around the neck, mark where it overlaps, then measure the marked length against a ruler.

How do I measure my dog for a harness?

Measure the chest girth at the widest part of the rib cage, just behind the front legs, and add 2 to 5 cm depending on the coat. Once it is on, two fingers should fit under every strap.

How often should I recheck the fit?

Every four to six weeks for a puppy under 12 months, and every few months for an adult dog, plus any time the dog's weight or coat changes noticeably.

MVM SitHappens is a dog lifestyle brand founded in Switzerland, making breed-specific apparel and accessories for dogs and the people who love them.