Dog Collar Size Chart by Breed: How to Measure Neck Size Correctly
Quick Answer: Measuring Your Dog for a Collar
Measure around the base of your dog’s neck (where a collar naturally sits) with a soft tape measure, add two fingers’ width for comfort, and use that number — not a generic breed-average chart — since individual dogs within the same breed vary enough that a chart alone can be wrong.
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As a CPDT-KA certified trainer, breed-average charts are a reasonable starting point for shopping, but the only measurement that actually matters is your specific dog’s own neck, taken correctly.
How Do You Measure Correctly?
Wrap a soft tape measure (not a rigid ruler) around the lower part of the neck, close to the shoulders, where a properly fitted collar sits. Snug but not tight — you should be able to slide two fingers flat between the tape and the dog’s neck.
Typical adult neck-size ranges by broad size category — illustrative starting ranges, not a substitute for measuring your own dog. Always confirm against your dog’s actual measurement.
Why Does “Add Two Fingers” Matter So Much?
Too tight restricts breathing and can cause tracheal strain over time with sustained pressure; too loose risks the dog backing out entirely. The two-finger rule is a practical, repeatable check that works regardless of breed.
Should You Re-Measure Over Time?
Yes — puppies obviously grow, but adult dogs’ neck size can also shift with weight change or thick seasonal coats. Re-check the fit every few months, not just at purchase.
Measuring Step by Step
Breed charts give a starting range, but dogs within a breed vary a lot, so always measure your own. Use a soft tape (the sewing kind), wrap it around the base of the neck where a collar naturally sits, and add the extra room for comfort. A good fit leaves room for two fingers under the collar. Re-measure puppies every couple of weeks, since they grow fast.
The iBayam soft measuring tape is the kind of flexible tape you want; a rigid ruler won’t wrap properly. Once you have the number, compare it to the size chart for the product, for example the Joytale reflective collar or the Joytale martingale collar, as each brand’s sizing differs.
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Common Mistakes
- Measuring over thick fur without pressing it flat.
- Choosing by weight or breed alone.
- Buying at the very top of a size range, leaving no room to adjust.
- Forgetting that martingales need a different fit from flat collars.
For choosing collar types, see our dog collar guide and collars guide for fit and material. View the Joytale reflective collar on Amazon and check its size chart against your measurement.
When to Re-Measure
Puppies can outgrow a collar in weeks, and adult dogs change with weight loss, weight gain or a thick winter coat. Re-measure every few months, and any time the collar looks tight or the ID tags seem to sit differently. Wear matters too: a collar that has stretched with age may be looser than the size label implies. If you’re replacing a collar, measure first instead of assuming the old size still fits.
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FAQ
Does this chart apply to harnesses too?
No — harness sizing uses chest girth, not neck circumference. See our harness sizing guide for that measurement.
What if my dog is between two sizes?
Size up and use the adjustment range built into most collars, rather than sizing down and risking a too-tight fit.
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