What Size Collar for German Shepherd Puppy? | Fit As They Grow

Picking the right collar size for a German Shepherd puppy comes down to one thing: the pup’s neck measurement today, not the 24-inch neck they’ll have as an adult.

Measure Your Puppy’s Neck First

Grab a soft measuring tape and wrap it around your puppy’s neck where the collar will actually sit — roughly halfway between the back of the head and the shoulders. Pedigree’s collar guidance for German Shepherds recommends this spot for the most reliable measurement.

Add about one inch to that number for comfort. The finished collar should let you slip two fingers between the fabric and your puppy’s neck — snug enough that it won’t slip over the head, loose enough that it never presses.

If you’re between sizes, size up and tighten the adjuster. A collar that’s too tight can rub sores, while one that’s too loose can slip off entirely.

What Size Works For Each Growth Stage?

German Shepherd puppy sizing follows a rough curve. While individual puppies vary, most follow a predictable pattern:

• 2 months: Neck around 8–10 inches, suiting a small or medium adjustable collar with a 1/2-inch to 3/4-inch width.
• 4 months: Usually 10–12 inches, still in that small-to-medium range but often on the looser adjustment holes.
• 6 months: Neck near 12–14 inches, most puppies moving into a medium collar with a 3/4-inch width.
• Adult (18+ months): Common range of 16–24 inches, typically an L/XL collar with a 1-inch width.

That adult 1-inch width matters more than it seems. A wider collar distributes pressure across a broad surface, which helps prevent the collar from slipping and reduces strain on the neck when your dog pulls on leash.

The actual measurement of your puppy’s neck is the number that decides the purchase.

Why Adjustable Collars Are The Practical Choice

German Shepherd puppies outgrow collars quickly. Most large-breed dogs need two or three collar sizes over their lifetime, and a puppy that gains several pounds a week can outgrow a fixed-size collar in under a month.

An adjustable collar gives you weeks or months of extra room before you need to buy the next size. Look for one with a good range of adjustment holes — the more room to grow, the longer the collar stays useful.

For a roundup of collars that hold up through the chewing and pulling phases, this list of the best German Shepherd puppy collars covers options sized and tested for the breed.

Fit Checks And Common Sizing Mistakes

Check the fit every few days while your puppy is growing fast. The two-finger rule is the standard test — if you can’t comfortably fit two fingers under the collar, it’s too tight. If the collar slips over the head easily, it’s too loose.

Don’t size a puppy collar from adult weight. Breed averages and weight charts are useful for adult dogs, but a rapidly growing puppy’s neck circumference changes week to week. The current measurement always wins.

Also remember that every brand sizes slightly differently. PetSmart’s dog collar sizing chart and Pedigree’s German Shepherd guidance both emphasize using the manufacturer’s specific chart for each product. A “medium” from one brand can fit differently than a “medium” from another.

One more note: prong or training collars follow completely different rules than flat collars. Those sit high behind the ears and should never be sized like an everyday flat collar. If you’re using one, follow the manufacturer’s specific guidance for that tool.