How to Measure Your Dog for a Custom Collar: The 5-Minute Guide to the Perfect Fit

A collar failure in a busy park rarely comes from cheap hardware or a snapped buckle. It comes from fit. A dog slips a collar that looks fine, costs $60, and has a GPS tracker attached to it. The owner is left holding a leash connected to nothing.

That scenario plays out regularly, and it points to a gap that material comparisons rarely address: durability without fit is just aesthetics. The collar can resist water, hold its color for years, and outlast the dog's puppyhood. None of that matters if it was sized wrong on day one.

What you need to measure your dog

You need a soft measuring tape, the kind tailors use. The fabric ones work better than metal tape measures because they conform to your dog's neck without gaps. If you don't have one, use a piece of string and measure it against a ruler afterward.

Grab some treats so that your dog cooperates. Most dog love to play along when there is food involved.

Get a notepad or open your phone's notes app. Write the number so that you do not forget it the next day. If your dog is anxious, you can call someone for help to steady the dog while you measure. Or vice versa.

The three-step measuring process

Step 1: Find the right spot

The collar sits at the base of your dog's neck, not up high near the ears or down low on the shoulders. Place two fingers at the top of your dog's shoulder blades and slide them up toward the head. Stop when you feel where the neck starts to widen. That's your measuring spot.

This is where where the collar naturally rests during walks. Measure too high and the collar will slide down. Measure too low and it will ride up and choke.

Step 2: Take the measurement

Wrap the measuring tape around your dog's neck at that base point. Pull it snug but not tight. You should feel slight resistance, like a comfortable watch band.

Here's the two-finger rule: slide two fingers between the tape and your dog's neck. If you can fit two fingers comfortably side by side, that's the right tension. If you can fit three or four fingers, it's too loose. If you can barely squeeze one finger in, it's too tight.

Read the measurement where the tape meets itself. Write down the exact number in inches or centimeters.

Step 3: Add comfort space

Take your base measurement and add 1 to 2 inches for the collar size.

For small dogs under 20 pounds, add 1 inch. For medium dogs between 20 and 50 pounds, add 1.5 inches. For large dogs over 50 pounds, add 2 inches.

Dogs with thick coats need extra room. Add another half inch for breeds like huskies, malamutes, or golden retrievers. The fur compresses when wet or during summer shedding, so you need that buffer.

Short-haired breeds like pit bulls or boxers can stick to the standard additions. Their skin sits closer to the surface and you get a more accurate base measurement.

This final number is your custom collar size.

Common measuring mistakes

Most people measure over the fluffiest part of their dog's fur and wonder why the collar arrives too big. You're measuring the neck, not the fur. If your dog has a thick coat, press the tape down gently so it touches skin.

Dogs who are jumping, panting, or pulling away will shift the tape position. Wait until your dog is calm. Measure after a walk when they're tired, not before when they're excited.

Do not forget the two-finger rule. Some owners skip it and just eyeball the fit. That's how you end up with collars that slip off or restrict breathing.

Puppies grow fast. If your dog is under a year old, you'll need to re-measure every month. That custom collar you ordered in January might not fit by March. Buy adjustable collars for puppies or plan to replace them frequently.

Measuring at the wrong spot throws off everything. The neck gets wider as you move toward the shoulders and narrower as you move toward the head. Measure at the base where the collar will actually sit.

Special considerations by dog type

How to measure puppies

Add 2 to 3 inches to a puppy's base measurement instead of the standard 1 to 2 inches. They'll grow into it within weeks.

Re-measure every 4 weeks until your dog reaches full size. Most breeds hit that point between 12 and 18 months, though large breeds can keep growing until age 2.

Adjustable collars work better for puppies than custom-fitted ones. You'll save money and reduce waste by buying one collar that expands as they grow.

Breeds with unique neck shapes

Greyhounds, whippets, and other sighthounds have necks wider than their heads. A standard collar can slip off even when properly sized. Measure at the widest part of the neck, right behind the ears, and add 1 inch. Martingale-style collars work better for these breeds because they tighten slightly when the dog pulls.

Bulldogs, pugs, and French bulldogs have thick necks and almost no taper from head to shoulders. Measure around the middle of the neck rather than the base. Add only 1 inch regardless of size because these breeds don't need much extra room.

Long-haired breeds like collies, Samoyeds, and Newfoundlands require an extra step. Measure with the coat dry and at full thickness. Then press the fur down and measure again at skin level. Split the difference between those two numbers and add 2 inches. This accounts for seasonal shedding and wet weather compression.

Active dogs and escape artists

Dogs who slip out of collars need a snugger fit. Use the two-finger rule but aim for a firm two-finger fit rather than a loose one. Add only 1 inch to the base measurement.

If your dog backs out of collars regularly, the problem might not be the measurement. It might be the collar style. Martingale collars tighten when dogs pull backward, preventing escapes without choking.

Why custom-fit collars are worth it

Your dog wears a collar 12 to 16 hours a day. A collar that fits correctly becomes invisible to them. They don't scratch at it. They don't try to rub it off on furniture. They move naturally without adjusting their gait or head position.

Dogs in poorly fitted collars develop behavior problems. A collar that's too tight makes them anxious. They associate the discomfort with walks and start resisting the leash. A collar that's too loose creates a different problem. The dog learns they can back out of it, and suddenly every walk becomes a negotiation.

Safety depends on proper fit. A collar that slips off turns a routine walk into an emergency. A collar that's too tight can damage the trachea, especially in small breeds or dogs who pull. Veterinarians treat collar injuries every week, from minor skin irritation to serious neck trauma.

Collars that fit last longer. When a collar moves around constantly, the hardware rubs against the same spots. Buckles wear through fabric. D-rings create stress points. A properly fitted collar distributes pressure evenly and the materials age slowly instead of failing at weak points.

Custom measurements unlock better style options. Standard sizes force you to choose from whatever fits your dog's approximate neck size. Custom sizing means you pick the style, color, and features you actually want. The collar gets built to your specifications instead of you settling for close enough.

GPS and AirTag collars require exact fit. The tracking device needs to sit in a specific position to work correctly. A loose collar means the tracker bounces around and drains battery faster from constant movement. A tight collar pushes the device against your dog's neck and causes irritation. Purespet's custom collars position tracking technology based on your dog's exact measurements, keeping the device stable and your dog comfortable.

Professional collar makers build to your numbers, not to broad size categories. The difference between a 15-inch neck and a 16-inch neck matters when you're paying for custom work. You get exactly what you measured for, not a range that might work.

Why brands must be specific about dog collar sizing

A customer orders a collar marked "medium" from your website. It arrives and doesn't fit their 45-pound border collie. They leave a one-star review saying your sizing is wrong. Three potential customers read that review and buy from a competitor.

The collar wasn't actually wrong. The customer measured incorrectly or their dog fell between standard sizes. But you still lost those sales because generic size labels create confusion.

Brands that provide exact measurements in inches or centimeters alongside size labels reduce returns by up to 40%. When a product page says "Medium: 14-16 inches" instead of just "Medium," customers can verify the fit before ordering.

Bad sizing costs money in three ways. First, returns eat into profit margins. Shipping a replacement collar costs you $8 to $12 in both directions. Second, negative reviews damage your ranking in search results and marketplace algorithms. One string of poor reviews about sizing can drop your product listing from page one to page three on Amazon. Third, customer trust disappears after one bad experience. That customer won't give your brand a second chance.

Brands that nail sizing build trust. Customers who get the right fit the first time come back for leashes, harnesses, and replacement collars. They recommend your brand to other dog owners. They leave positive reviews that mention how accurate the sizing guide was.

Vague sizing creates distrust. Customers start wondering what else you got wrong. If you can't provide clear measurements for something as basic as a collar, why should they trust your claims about durability or materials?