How do I choose a dog collar size from a size chart?

Measure around the neck where the collar normally rests, allow a comfortable two-finger fit, and choose a size that places the measurement inside the adjustment range rather than at an extreme.

What if my dog's neck measurement falls between two sizes?

Compare where the measurement sits within each adjustment range, consider coat and growth changes, and contact support before personalizing if neither option provides comfortable room on both sides.

Can I choose collar size by breed or weight?

No. Dogs of the same breed or weight can have different neck and head shapes. Use a current neck measurement instead of a breed or weight estimate.

Dog Collar Size Chart & Measurement Checklist

Four adjustable OPTCLA personalized dog collars shown for size selection

Do not select size from breed, age or weight alone. Fit varies by neck shape, head shape, coat and activity. The Trail ID Collar is not tie-out equipment.

OPTCLA dog collar size chart

Size	Adjustable neck range	Choose it when
Small	10-14 in	Your measured fit sits comfortably within this range.
Medium	13-18 in	Your measurement has usable adjustment room on both sides.
Large	16-22 in	The current fit is not at the minimum or maximum limit.
XL	19-27 in	The range fits today without relying on an oversized setting.

Five-step measurement checklist

Use a soft tape. Place it around the base of the neck where the collar normally rests.
Keep the tape level. Do not angle it toward the head or shoulders.
Allow a two-finger fit. Two fingers should slide beneath the tape without forcing them.
Record the number in inches. Measure again before relying on the first result.
Compare the full range. Choose a size that leaves usable adjustment room rather than placing the measurement at an extreme.

Why measuring an old collar can mislead

A collar laid flat does not always show the fitted circumference. Buckles overlap, adjustment hardware changes the usable length and owners may measure from the wrong points. Measuring the dog's neck directly is clearer unless the old collar's fitted reference points are known.

If the measurement overlaps two sizes

Several OPTCLA ranges overlap intentionally. Compare how much adjustment remains above and below the current measurement. Consider coat changes and puppy growth, but do not choose a loose collar simply for future room. Contact OPTCLA support before personalizing when the fit sits near a range limit.

Complete the fit check after fastening

After the collar arrives, adjust it and repeat the two-finger check. Gently confirm it does not pass over the head. Recheck after grooming, bathing, seasonal coat changes, weight changes and growth. The complete dog collar fit guide explains these checks in more detail.

Before you submit personalization

Confirm the size and color shown in the order review.
Check every character in the pet name and phone number.
Use a phone number that can help someone reach you.
Read the personalized return and engraving-error policy.
Review the production and delivery timeline.

For puppies and changing coats

Measure the neck your dog has today. Puppies and dogs with dense seasonal coats need more frequent checks; use the puppy growth and sizing guide to plan remeasurement. If you are comparing general size labels, read the small, medium and large dog collar fit guide before choosing.

Choose size and personalize

Frequently asked questions

Can I choose size by breed?
No. Measure the individual dog's neck because dogs of the same breed can fit differently.

What if the measurement is exactly at a size limit?
Choose a range that gives usable adjustment room, or contact support before personalizing.

How often should I remeasure?
Remeasure after growth, grooming, coat or weight changes, and whenever the collar begins to sit differently.

Is the two-finger check enough by itself?
It is a useful starting point, but head shape, coat, activity and the equipment used also matter.

Measure first. Personalize with more confidence.