Measure your dog’s neck at its base where the collar rests, then add two fingers of slack so the collar is snug but never tight.
Ordering a personalized collar is exciting, but the thrill dies fast if it arrives too loose or too tight. The good news is that measuring your dog at home takes about two minutes with nothing more than a flexible tape measure or a piece of string. Here’s the method that works, plus the details that decide whether the fit is comfortable or a constant annoyance.
Where Exactly Should You Measure?
Measure at the base of the neck, right where the collar naturally sits — not high up near the jaw. This is the widest part of the neck, so sizing here guarantees the collar won’t choke when the dog pulls or lowers its head.
Use a flexible sewing tape measure. If you don’t have one, a piece of string works just as well:
- Wrap the tape or string around the dog’s neck at the base.
- Keep it snug but not tight — the tape should touch fur without pressing into skin.
- If using string, mark where the ends meet, then lay it flat against a ruler.
PetSmart’s sizing guide and Coastal Pet both recommend leaving enough room for two fingers to slip between the neck and the collar. That’s your comfort target: tight enough that the collar won’t slip over the head, loose enough that it never digs in.
Use an Existing Collar As a Shortcut
If your dog already wears a collar that fits well, you can skip the tape entirely. Lay that collar flat on a table and measure it properly.
For a standard buckle collar, measure from the center of the buckle to the hole you actually use. For a side-release style, measure the full length from one end to the other. That number is your dog’s effective neck size.
This shortcut works because it measures the leather or nylon at the size your dog already wears, not a guess based on breed or weight. Breeds vary widely within the same weight range — a lean Greyhound and a stocky Lab can weigh the same but need completely different collars.
One caveat: Coastal Pet notes that some collars sit higher on the neck than others. If switching from a low-riding everyday collar to a training collar that rides higher, measure fresh with the tape method instead of trusting the old collar’s length.
Special Cases: Slip Collars and In-Between Sizes
Slip collars and over-the-head styles change the math. For these, measure around the widest part of the dog’s head as well — usually just behind the ears and across the cheeks — because the collar has to pass over the skull before it reaches the neck. Valisco Pet Supply’s guide specifically calls this out.
When your measurement falls between two sizes on a brand’s chart, don’t stress. Some manufacturers recommend sizing up for growing puppies or long-haired breeds, while others recommend the smaller size for a snugger fit.
Here’s the rule that settles it: the brand’s own size chart controls. Each company builds its collars slightly differently, and a “large” from one maker can measure like a “medium” from another. Check the specific chart on the exact collar listing before you order, not a generic dog-size table.
For most adult dogs with a settled weight, dogIDs’ sizing guide recommends measuring the neck fresh with a sewing tape or string rather than trusting a guess — it takes less than a minute and removes the risk entirely.
Turning Your Measurements Into the Right Collar
With your base-of-neck measurement and your two-finger slack rule, you now have everything needed to order with confidence. It’s a far better strategy than buying on looks alone, since recutting and personalization fees rarely make exchanges worthwhile.
Before you check out, confirm the collar’s width suits your dog’s size — heavier dogs need wider collars for better weight distribution — and double-check the personalization character limit so the name actually fits.
If you’re comparing materials, hardware, and personalization options across brands, our guide to the best personalized dog collars breaks down the top picks side by side, so you can match your measurements to the right product without digging through dozens of listings.
| Collar Type | What To Measure | Fit Rule |
|---|---|---|
| Standard buckle | Neck base, or existing collar from buckle center to used hole | Two fingers of slack under the collar |
| Side-release | Neck base, or existing collar end to end | Two fingers of slack under the collar |
| Slip / over-the-head | Neck base plus widest part of the head | Must pass over skull, then sit snug at neck |
| Between sizes | Check brand’s size chart for that exact collar | Follow the brand’s recommendation |
The whole process comes down to three numbers: the base-of-neck circumference, the head circumference for slip styles, and your two-finger check. Nail those and the personalized collar you order will be the one your dog actually wears every day.
FAQs
Can I measure my dog with a piece of string instead of a tape measure?
Yes. Wrap the string around the base of the neck, mark where the ends meet, then lay the string flat against a ruler. This gives the same result as a flexible measuring tape and is easier if you don’t have one at home.
What if my dog is between two collar sizes?
Follow the brand’s own size chart for the exact collar you want. Some brands recommend sizing up, others recommend sizing down, so the manufacturer’s guidance for that specific product always wins over a generic rule.
How tight should a dog collar be after measuring?
The collar should be snug enough that two fingers slip between the collar and your dog’s neck comfortably. If you can fit more than two fingers, it’s too loose; if two fingers feel tight, it’s too snug.
References & Sources
- PetSmart. “Sizing Charts.” Provides the two-finger fit rule for dog collars.
- dogIDs. “Sizing Guides.” Details measuring with a sewing tape or string, plus the flat collar measuring method.
- Coastal Pet. “Sizing Guide.” Covers collar placement higher on the neck and the two-finger comfort rule.