How To Measure A Dog's Neck For A Collar
Learning how to measure a dog's neck for a collar takes about a minute and saves you from the much less fun experience of ordering the wrong size.
Wrap a soft measuring tape around your dog's neck where the collar naturally sits. Keep the tape snug without pulling it tight, and make sure you can comfortably slide two fingers between the tape and your dog's neck.
That number is your starting point.
Then compare the measurement with the actual size chart for the collar you're buying.
Dog collar sizing isn't standardized across brands, so a medium from one brand isn't necessarily a medium somewhere else.
Simple enough.
But a few small details make the difference between a collar that fits beautifully and one that spends its life in a drawer.
Where to measure your dog's neck
Measure around the part of your dog's neck where their everyday collar naturally rests.
For most dogs, that's around the middle portion of the neck, above the shoulders rather than directly underneath the jaw.
Keep the measuring tape flat against the coat without twisting it.
Don't pull it tightly against the skin.
The goal isn't to find the smallest possible measurement. It's to recreate how the collar will actually sit when your dog is wearing it.
The American Kennel Club also recommends measuring your dog's actual neck rather than relying on weight alone when choosing a collar.
How to measure a dog's neck for a collar
A flexible fabric measuring tape is easiest.
Once you have one, the process is pretty simple.
- Have your dog stand or sit normally. Keep their neck in a natural position rather than stretched upward or tucked down.
- Find where the collar normally sits. Wrap the measuring tape around that part of the neck, keeping it flat and untwisted.
- Pull the tape snug, but not tight. It should rest against your dog's coat without digging into the neck.
- Check the space with two fingers. You should be able to slide two fingers flat between the tape and your dog's neck without forcing them in.
- Write down the measurement. Don't round based on what size you think your dog should wear.
- Compare that number with the brand's size chart. Choose the size based on the listed neck circumference rather than breed or weight.
And yes, actually measure.
Your 22-pound Frenchie and someone else's 22-pound Frenchie can have very different necks.
No measuring tape? No problem.
You don't need a fabric measuring tape to get an accurate dog neck measurement.
Grab a piece of string, ribbon, charging cable, or another flexible item that doesn't stretch.
Wrap it around your dog's neck where the collar will sit.
Hold or mark the point where the two ends meet, then lay it flat and measure that length with a ruler or standard tape measure.
Avoid anything stretchy.
A stretchy cord can give you a measurement that looks perfectly legitimate right up until the collar arrives and very much isn't.
Can you measure your dog's current collar instead?
Yes, especially if your dog already owns a collar that fits perfectly.
But don't simply measure the entire collar from one physical end to the other.
Buckles overlap, hardware adds length, and different collar constructions close differently. The total length of the collar may not represent the circumference around your dog's neck.
Instead, fasten the collar at the setting your dog normally wears.
Measure the usable inside circumference of the fastened collar.
That gives you a much better representation of your dog's actual collar size.
When possible, measuring your dog directly is still the most reliable option.
Dog collar fit at a glance
A measurement gets you to the right size range.
The final fit tells you whether the collar actually works for your dog.
| Collar fit | Good fit? | What to look for |
|---|---|---|
| Too tight | No | Two fingers won't slide comfortably underneath, or the collar presses into the neck |
| Snug with two-finger room | Yes | Two flat fingers fit underneath with light resistance and the collar stays securely in place |
| Loose or visibly gapping | No | Collar shifts excessively or leaves a noticeable gap around the neck |
| Able to slip over the head | No | Collar may be too large or too loose to stay secure |
| Growing puppy | Recheck often | A good fit can become tight quickly, so check the adjustment as your puppy grows |
| Thick or seasonal coat | Recheck | Shedding and coat changes can affect how snugly the same collar fits |
A properly fitted collar should feel secure without squeezing the neck.
If you can barely get one finger underneath, loosen it.
If you can pull the collar over your dog's head without unbuckling it, it's too loose.
The goal is a collar that stays where it belongs while leaving enough room for your dog to move, breathe, and go about the extremely demanding business of being a dog.
The two-finger rule
You've probably heard that you should be able to fit two fingers underneath a dog's collar.
That's a good rule.
But how you do it matters.
Put the collar on your dog and slide your index and middle fingers flat between the collar and the neck.
You shouldn't have to force them underneath.
At the same time, there shouldn't be a large gap around your fingers or enough slack that the collar can easily pull over your dog's head.
Two fingers with light resistance is what you're looking for.
This is a fit check, not an instruction to add several inches to your dog's actual neck measurement before shopping.
Measure the neck first.
Choose the appropriate size range second.
Then use the two-finger rule to check the finished fit.
Pink Papyrus dog collar sizing at a glance
Our adjustable collars are designed with overlapping size ranges so you can fine-tune the fit rather than relying on a single fixed circumference.
| Dog's neck | Pink Papyrus size | Notes |
|---|---|---|
| 8–12 inches | XS | 5/8-inch collar width |
| 11–16 inches | S | 5/8-inch collar width |
| 13–19 inches | M | 1-inch collar width |
| 18–28 inches | L | 1-inch collar width |
Notice that some of the size ranges overlap.
That's intentional.
An adjustable collar gives you room to fine-tune the fit rather than requiring every dog to conveniently have a neck that falls into a perfectly tidy size category.
For a broader breakdown of sizing, including common breed examples, see our Ultimate Dog Collar Size Guide.
What if your dog falls between collar sizes?
This is where the actual measurement matters more than the letter on the tag.
If your dog's neck measurement falls into two overlapping size ranges, look at where the number lands within each collar's adjustable range.
You generally want room to adjust the collar in either direction rather than having it tightened or loosened completely to its limit.
Your dog's build matters too.
A dog with a thick neck and relatively narrow head has different security considerations than a dog whose head is considerably wider than their neck.
Don't choose a collar simply because your dog's weight seems to match a particular size.
There is no universal dog collar sizing standard, and two dogs at exactly the same weight can have very different neck circumferences.
Measure the dog in front of you.
Not the imaginary average version of them on a breed chart.
Measuring a puppy for a collar
Puppies have a slightly annoying habit of growing.
Sometimes very quickly.
Measure a puppy's neck using the exact same method you would use for an adult dog, then choose an adjustable collar that fits securely at their current size.
Don't buy an oversized collar because you expect them to grow into it.
The collar still needs to fit safely today.
Once your puppy starts wearing it, check the two-finger fit frequently.
A collar that fit perfectly a few weeks ago can become too snug without looking dramatically different from the outside.
Also keep an eye on the adjustment range.
If you're already approaching the maximum length of the collar, it's probably time for the next size.
Measuring dogs with thick or fluffy coats
Thick fur can make measuring a dog's neck slightly trickier.
Don't cinch the measuring tape down until you've completely flattened the coat against the skin.
That can result in a finished collar that's tighter than you intended.
Instead, measure where the collar naturally rests over the coat without artificially fluffing or compressing the fur.
Then check the actual collar with the two-finger rule once it's on.
Dogs with heavy or seasonal coats may need their collar adjusted throughout the year as their coat changes.
Yes, apparently their wardrobe has seasons too.
Common dog collar measuring mistakes
The actual measuring process is easy.
These are the little things that tend to throw it off.
Guessing based on breed or weight: Breed and weight can give you a rough idea, but individual dogs vary too much for either one to replace an actual neck measurement.
Choosing a size without checking the brand's chart: There is no universal small, medium, or large dog collar. Use the measurements listed for the specific collar you're buying.
Measuring the wrong part of the neck: Measure where the collar will actually sit, not the narrowest part of the neck you can find.
Pulling the measuring tape too tight: You're fitting a collar, not taking a tailor's measurement for a fitted tuxedo.
Adding too much extra room: The collar needs to be comfortable, but it also needs to stay securely on your dog.
Measuring an existing collar from end to end: Hardware and buckle overlap can make that measurement misleading.
Measuring once and assuming you're set forever: Puppies grow. Adult dogs gain and lose weight. Coats change. Check the fit periodically.
How to check the fit once the collar arrives
Don't stop at "it buckled."
Put the collar on your dog and adjust it until two fingers fit comfortably underneath.
Then watch your dog move.
Have them walk around, sit, turn their head, and lower their nose toward the floor.
The collar should stay in place without digging into the neck, creating obvious pressure points, or becoming loose enough to slip over the head.
Also watch what happens when the leash is attached.
If your dog pulls heavily, coughs against leash pressure, or has a neck or respiratory condition, a harness may make more sense for walks. Our guide to whether a harness or collar is better for your dog goes deeper into the differences.
For more general information about safe collar use, the ASPCA recommends checking collars regularly as dogs grow and making sure they aren't fitted too tightly.
The measurement tells you what to order.
Your dog moving around in it tells you whether the fit actually works.
The practical next step
Measure first.
Shop second.
It sounds obvious, but it's the easiest way to avoid the sizing roulette that happens when we decide a dog "looks like a medium."
Measure your dog's neck where the collar naturally sits.
Match that number to the actual size chart.
Once the collar arrives, adjust it, do the two-finger check, and watch your dog move around in it.
If something looks off, adjust and check again.
Browse our Dog Collars for adjustable designs made with reinforced stitching, durable hardware, and enough personality to make the practical part considerably more fun.
Because the collar needs to fit correctly.
It can also be ridiculously cute.
Frequently asked questions
How do I measure my dog's neck for a collar?
Wrap a soft measuring tape around your dog's neck where the collar naturally sits. Keep it snug without pulling it tight, then check that you can comfortably slide two fingers between the tape and the neck. Use that measurement with the size chart for the specific collar you're buying.
How tight should a dog collar be?
A properly fitted dog collar should be snug enough to stay securely in place while leaving room for two fingers between the collar and your dog's neck. If you can't comfortably fit two fingers underneath, loosen it. If the collar gaps significantly or can slip over the dog's head, it's too loose.
Should I add inches to my dog's neck measurement?
Not automatically. Measure your dog's actual neck and follow the manufacturer's size chart. Adding arbitrary extra inches can result in a collar that's too loose. Use the two-finger rule to check the finished fit instead.
What can I use if I don't have a soft measuring tape?
Use a non-stretchy piece of string, ribbon, or flexible cord. Wrap it around your dog's neck where the collar normally sits, mark where the ends meet, then lay it flat and measure it with a ruler or standard tape measure.
Can I measure an old collar instead of my dog's neck?
Yes, if the collar currently fits correctly. Fasten it at your dog's normal setting and measure its usable inside circumference rather than measuring the entire collar from end to end. Buckles and hardware can add length that isn't part of the actual neck circumference.
Should I size up if my dog is between collar sizes?
If your dog's measurement fits within two overlapping adjustable ranges, look at how much adjustment each size leaves in either direction. You want a collar that can be adjusted securely without sitting at its absolute smallest or largest setting whenever possible.
How often should I check my dog's collar fit?
Check the fit periodically and anytime your dog's body or coat changes noticeably. Puppies need more frequent checks because they can outgrow collars quickly. Adult dogs may need adjustments after weight changes or seasonal coat changes.
Is it better to measure a dog's neck or choose a collar by weight?
Measure the neck. Weight can give you a rough starting point, but dogs at the same weight can have very different neck circumferences. Your dog's actual neck measurement is the more reliable way to choose a collar size.
