How to Measure a Dog Collar Size

A good collar fit begins with a simple measurement. Measuring before you order helps you compare your dog’s neck size with the product’s size range and reduces the chance of a collar that slides around or feels restrictive.

What you need

Use a soft tape measure. If you do not have one, wrap a piece of string around the neck, mark where the ends meet, then measure the string with a ruler. Measure when your dog is calm and standing naturally.

Measure where the collar will sit

1. Place the tape around the base of the neck, where your dog normally wears a collar.
2. Keep it snug against the coat but do not pull it tight.
3. Record the measurement in centimetres and inches if the product size chart uses both.
4. Compare that number with the product’s stated adjustable range—not only with a breed or weight guide.

Do the two-finger fit check

Once the collar arrives, fasten it and slide two flat fingers between the collar and your dog’s neck. The goal is comfortably snug, not loose enough to slip over the head and not tight enough to press into the coat. Recheck the fit after grooming, coat changes or growth.

Common sizing mistakes

Do not measure an old collar laid flat unless you also know where it was buckled; the usable length matters more than the total strap length. Avoid relying only on breed labels because dogs of the same breed can have very different neck shapes. For a puppy, measure regularly as growth can be quick.

A collar is not a substitute for safe handling. If your dog coughs, struggles, scratches persistently or seems uncomfortable, remove the collar and ask a veterinarian or qualified trainer for guidance.