Dog collar size calculator

How do you measure a dog's neck for a collar?

Use a soft tape measure, or a piece of string you then lay against a ruler. Measure with your dog standing, which the AKC recommends for every gear measurement.

1. Find the base of the neck, where a collar naturally sits.
2. Start the tape at the ridge between the shoulder blades and wrap it round to the front of the chest and back.
3. Slide two fingers between the tape and the neck before you read it. This is the AKC's two-finger rule, and it builds the comfort room into the number.

Measured that way, the number on the tape is the collar size. Mendota Pet says the same: there is no need to add inches. Some makers work differently. LupinePet has you measure snugly and add 5% for comfort, so a 15 in neck measured snug becomes 15.75 in:

Collar size = snug neck × 1.05 (LupinePet) · or · neck measured with two fingers under the tape (AKC, Mendota)

The calculator handles both: tell it how you held the tape.

Dog collar size chart

Most collars adjust over a range, so the useful question is which range your dog's neck falls in. This chart is computed from the same data as the calculator, using LupinePet's rule of picking the smallest range that fits.

Ruffwear sells the Front Range collar in three ranges (11–14 in, 14–20 in, 20–26 in). When a neck sits exactly on the line between two ranges, the chart picks the one that leaves room to loosen. Mendota's standard buckle collars are ordered by neck size and adjust 2 inches smaller or larger.

Measuring a collar that already fits

If your dog has a collar that fits well, you can skip the tape on the dog. Lay the collar flat and measure from the middle of the buckle to the hole it is fastened on. That is the method Mendota gives, and the number is your dog's collar size. Choose "A collar that fits" in the calculator to use it.

Don't measure the whole strap end to end: collar length includes the buckle and the spare tail, so it is always longer than the neck it fits.

How tight should a dog collar be?

You should be able to slide two fingers between the collar and the neck. The RSPCA's shop adds a useful detail: the fingers go in on their edge, not flat. Then check two things:

• Too loose: the collar slides over the ears when you pull it gently forward, so your dog could back out of it.
• Too tight: you can't get two fingers under it, or you see rubbed fur or red skin under the collar.

Puppies grow fast, so check the fit every week or so and let the collar out as needed. Many owners of dogs that pull switch to a harness, which takes the pull on the chest rather than the neck; the harness size calculator reuses your neck measurement.

What collar width does my dog need?

Wider collars go with bigger necks. LupinePet's ranges show how the two pair up:

• 1/2 in wide: necks from 6 to 16 in (6–9 in, 8–12 in, 10–16 in)
• 3/4 in wide: necks from 9 to 25 in (9–14 in, 13–22 in, 15–25 in)
• 1 in wide: necks from 12 to 31 in (12–20 in, 16–28 in, 25–31 in)

Ruffwear uses 3/4 in webbing on its smallest Front Range collar and 1 in on the two bigger ones. If your dog has a long, thick coat, see our picks of collars for long-haired dogs.