When to Size Up a Puppy Collar (and How Often to Check)

The two-finger rule, and why it stops working

A puppy collar is correctly sized when you can slide two fingers flat between the webbing and your puppy's neck. When that gap shrinks to one finger, or when the hair underneath starts to mat and flatten, it's time to size up. For most puppies, that moment arrives every 3 to 6 weeks in the first six months of life.

I learned this the hard way with our first studio dog. We stitched her a collar at 9 weeks, told ourselves we'd check it on Sundays, and then forgot for ten days. The collar was still buckled on the same hole. Her neck wasn't.

Puppies grow in spurts, not curves. A Labrador puppy can add 1-2 cm of neck circumference in a single week between weeks 10 and 16. A Cane Corso or Rottweiler puppy can add even more. The collar you bought at 8 weeks is rarely the collar you're still using at 14 weeks, and that's not a flaw of the collar. That's biology.

How often to actually check the fit

The honest answer: more often than you think, and at predictable moments. Once a week is the right rhythm for the first six months. Pick a day: Sunday after the morning walk works for a lot of owners, and slide two fingers under the collar at the back of the neck. If the fit has tightened, loosen it one hole. If you've already run out of holes, it's time for the next size.

Beyond the two-finger test, here are the everyday signs the collar is getting tight:

• Hair under the collar starts to mat or flatten in a visible band.
• The skin underneath looks pink or irritated when you lift the collar.
• Your puppy scratches at the collar more than usual.
• You notice a faint pressure line in the coat after you take it off.
• The collar rotates less freely around the neck than it used to.

Any one of those is a green light to size up, or at least loosen by one hole if there's room left.

Why a Squffy Puppy collar adjusts across 4-6 cm

Most puppy collars give you 3-4 cm of adjustment range. The Squffy Puppy line is built with 4-6 cm of usable range across the holes, depending on size. That sounds small, but in puppy-growth terms it's roughly 4-8 weeks of extra wear before you outgrow the collar entirely.

The Puppy line specs, for context:

The 15 mm webbing matters. A puppy's neck is soft, the trachea is still developing, and a 25 mm or 38 mm adult collar puts pressure in the wrong places. Lighter webbing also means less weight pulling on a small frame, important when your puppy is still learning that a collar exists at all.

From our studio: the most-asked puppy sizing question is some version of "will my Cane Corso puppy fit this?" The honest answer is yes, but only for a few months. By 5-6 months, most power-breed puppies have moved out of the Puppy line and into a 25 mm Classic. We design the Puppy collar knowing it's a stepping stone, not a forever piece.

Power breeds: plan for 2-3 collars in the first year

If you've brought home a Cane Corso, Rottweiler, German Shepherd, Boxer, Mastiff, or any of the larger working breeds, here's the realistic collar timeline:

• Collar 1, 8 to 16 weeks. A 15 mm Puppy collar at the smallest setting. Neck circumference roughly 22-32 cm.
• Collar 2, 4 to 8 months. A 25 mm Classic, or a larger Puppy collar if your puppy is on the slower-growing side. Neck circumference 32-45 cm.
• Collar 3, 8 to 14 months. An adult collar, sized for where the dog actually is. Often a Tactical (Made by Squffy) for power breeds, given the load the buckle will eventually carry.

Smaller breeds (Cavaliers, Cockers, smaller terriers, French Bulldogs) often go through just one Puppy collar before settling into an adult Classic for life. The Puppy line carries them comfortably from 8 weeks until their neck stabilizes around 8-10 months.

Toy breeds may stay in a 15 mm collar permanently. That's fine. The Puppy webbing width is the right load for a 4 kg adult Yorkie just as much as it is for a 12-week Labrador.

What "sizing up" actually looks like

Sizing up doesn't mean buying the next collar size in the same line every time. It means matching the collar to where your puppy is now. A 6-month Cane Corso has the neck of an adult medium dog and shouldn't be in 15 mm webbing anymore, the puppy collar isn't engineered for that pull.

The signs you've outgrown the Puppy line entirely, not just the current hole:

• You're at the loosest hole and the fit is already snug.
• The dog can pull hard enough to flex the 15 mm webbing visibly.
• The zinc-alloy D-ring sits noticeably small against the dog's chest line.
• You're reaching for a stronger leash because the collar feels under-built.

At that point, move to a Classic (lifestyle, 25 mm (L/XL; S/M: 20 mm) webbing, zinc-alloy hardware) or a Tactical (engineered for power breeds, buckle tested to 360 kg, integrated control handle).

A note on embroidery and outgrowing collars

The hardest part of sizing up, for owners, not for the dog, is letting go of a collar with their puppy's name stitched on it. We get the email a lot: "Mila has outgrown her first collar. Can you make the next one with the same thread color?" The answer is yes, always.

You can keep the old collar. Plenty of customers do, a small drawer of outgrown puppy collars, one per dog, becomes a quiet timeline of the first year. Some ask whether they can send them back. A take-back programme is in development but not live yet, so for now it is the drawer or the hook. Most are kept on a hook by the door.

Sizing up isn't losing something. It's the puppy doing exactly what they're meant to do.

When to ask a vet, not a sizing chart

If your puppy's neck circumference jumps unusually fast (more than 3 cm in a week, repeatedly) or grows asymmetrically, mention it at the next vet visit. Most of the time it's normal growth. Occasionally it's worth checking. We don't know what's happening with every breed and every individual, your vet has hands on the dog and we don't.

For everything else: check on Sundays, slide two fingers under, and trust what you feel.