A correct collar fit comes from measuring the neck’s circumference at the spot the collar will actually sit, then checking that two fingers slide comfortably under the band.
A loose band lets a dog back out of it during a walk; a snug one rubs the coat and digs in at the throat. A soft tape measure, a still dog, and about a minute solve both problems, and the sizing chart only makes sense once you have the real number.
This guide covers where to measure, how to read brand charts, and what to do when your dog lands between sizes.
How Do You Measure A Dog’s Neck For A Collar?
Wrap a soft tape around the lower, narrowest part of the neck where the collar naturally rests, keep it snug but not tight, and note the circumference in inches. Coastal Pet’s sizing guide notes collars should sit higher than many owners assume, so measure the position the collar will occupy, not the widest part near the shoulders.
- Have the dog standing or sitting still.
- Keep the tape level all the way around.
- Leave room so two fingers slide under the tape.
- Record the number in inches, since US charts use that scale.
If the dog won’t hold still, an assistant holding a treat at eye level keeps the head steady. For a replacement collar, Coastal Pet and other makers describe a shortcut: lay the old collar flat and measure from the buckle center to the hole in use.
How To Measure A Dog’s Neck Without A Tape Measure
Use string or ribbon: wrap it the same way, mark where the end meets, then lay it flat against a ruler. The result is just as accurate if the string stays level and you mark it before it slips.
Side-release buckle collars add a wrinkle: some charts want the measurement from the female buckle end to the opposite end, excluding the male buckle portion, because the buckle adds length to the finished collar. Check the specific chart for the style you’re buying.
Dog Collar Sizing Chart And What Happens Between Sizes
Most US retailers publish neck ranges tied to collar size, and the spans overlap. PetSmart’s chart lists XXS at 6–8 in, XS at 8–12 in, S at 10–14 in, M at 14–20 in, L at 16–26 in, and XL at 24–30 in. A 15-inch neck falls inside both S and M, and that overlap exists because ranges aren’t interchangeable across brands. Collar width, buckle type, and product line all shift the effective fit, so chart values are a starting point, never a universal rule.
When the measurement lands inside two sizes, several brands advise the smaller one, unless the dog is still growing. A puppy headed toward adult weight is the clear exception; buy for the dog it will become.
| Collar Size | Neck Range | Fits Best For |
|---|---|---|
| XXS | 6–8 in | Teacup and toy puppies |
| XS | 8–12 in | Small breeds like Chihuahuas and Yorkies |
| S | 10–14 in | Terriers and small mixed breeds |
| M | 14–20 in | Beagles, Cocker Spaniels, mid-size dogs |
| L | 16–26 in | Labs, Boxers, most large adults |
| XL | 24–30 in | Great Danes, Mastiffs, giant breeds |
Ranges follow the PetSmart chart, which you can check against the live chart before ordering. For thick-coated or heavy-necked dogs — Huskies and similar spitz breeds — a wide band that spreads pressure beats a thin strap, and this collar guide for Huskies and thick-coated breeds is worth a look before committing to a width.
How Do You Know The Collar Actually Fits?
Slide two fingers flat under the band; they should pass with slight resistance, not easily and not with force. Some brands describe the gap as one or two fingers. A collar leaving a red mark or matted fur after an hour is too tight; one that slips over the head when pulled is too loose.
Puppies change fast, so recheck the two-finger gap every few weeks on a growing dog and adjust one hole at a time. If a collar rides against the throat while walking, loosen it; if it spins freely when the dog shakes, it’s too loose. A quick monthly check keeps a growing dog properly fitted.
FAQs
Can I measure my dog’s neck with a regular tape measure?
Yes. A soft tailoring tape gives the cleanest reading because it lies flat around the curve of the neck. A stiff retractable tape or metal ruler bends awkwardly and slips mid-wrap. If you only have a rigid tape, wrap string first, mark it, then measure the string flat.
Should I add anything to the neck measurement before ordering?
Most charts already account for the comfort gap built into the collar’s adjustability, so order based on the honest measurement. If the measurement sits right at the top of a range, moving up one size gives the buckle more holes. An accurate number beats guessing at extra inches.
How often should I recheck a growing puppy’s collar?
Every two to three weeks during rapid growth spurts, since a puppy can outgrow a collar in under a month. The two-finger check takes seconds and catches a too-tight band before it rubs. Once the dog reaches adult size, a monthly glance during grooming usually suffices.
References & Sources
- PetSmart. “Dog Collar Sizing Chart.” Source for the XXS–XL neck ranges used in this article.
- Coastal Pet. “Sizing Guide.” Source for collar placement on the neck and measuring a replacement collar.