Use this dog collar size calculator to find a size that's snug and safe — loose enough for two fingers underneath, tight enough that it can't slip over your dog's head.
Measure snugly around the middle of your dog's neck, where the collar will sit.
| Size | Neck circumference |
|---|---|
| XS | 9.5–12" |
| S | 12–16" |
| M | 16–19" |
| L | 19–23.5" |
General guide only — sizing varies by collar brand and by breed neck shape (e.g. sighthounds and breeds with thick necks often need adjustable or breed-specific collars). Always leave room for two fingers to fit flat under the collar.
Soft, breathable, adjustable nylon — sized to match your dog's neck circumference.
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Use a soft measuring tape (or a piece of string, then measure the string) around the middle of your dog's neck, roughly where a collar naturally sits. Keep it snug but not tight — you should be able to slip two fingers flat underneath.
If your dog is still growing, check their measurement again every few weeks and choose an adjustable collar with enough room to grow into. A collar that's too loose is a genuine safety risk — dogs can back out of it, especially narrow-headed breeds like Greyhounds and Whippets.
New breed data, growth tips, and puppy-parenting insights, plus our free printable puppy growth tracker.
