Vet Reviewed By: Dr. Allona Jackson, DVM
Dr. Jackson is a practicing veterinarian with over 12 years of experience in small animal care. She reviews all content on AvailPet.com for medical accuracy and pet safety.
Introduction
You’ve found the perfect collar. The color matches your dog’s eyes. The material is exactly what you wanted. The reviews are glowing.
Then it arrives. You buckle it around your dog’s neck. It’s either choking them or sliding over their head. Back to Amazon it goes.
Collar sizing isn’t intuitive. Most owners guess — and most owners guess wrong. A too-tight collar causes collar burn, tracheal damage, and constant discomfort. A too-loose collar means escape risk. The wrong size can turn a safety tool into a hazard.
I’m Dr. Allona Jackson, DVM. In this (How to measure dog collar size) guide, I’ll walk you through exactly how to measure your dog’s neck for a collar, introduce you to the two-finger rule, provide breed size charts, and tell you when to re-measure (most owners measure once and forget — that’s a mistake).
What You’ll Need (Tools)
Gather these items before you start:
- Soft fabric measuring tape (best option — flexible and accurate)
- OR: Piece of string or ribbon + a ruler (if you don’t have a soft tape)
- Pen and paper to write down measurements
- Treats to keep your dog still and cooperative
“A metal tape measure or carpenter’s tape is too stiff and won’t wrap around your dog’s neck accurately. Use soft, flexible material only.” — Dr. Jackson
Step-by-Step Guide to Measuring Your Dog’s Neck
Follow these five steps exactly for an accurate measurement.
Step 1: Position Your Dog Comfortably
Have your dog stand on all four paws — not sitting, not lying down. A standing dog has a naturally positioned neck.
If your dog won’t stay still, have a helper offer treats at nose level. Measure when your dog is calm and relaxed, not excited or anxious.
Step 2: Find the Right Spot on the Neck
Wrap the tape measure around the middle of the neck — NOT at the throat.
The correct spot is halfway between the ears and the shoulders. This is where the collar will naturally sit when your dog is walking.
- Too high (under the jaw): The collar will choke your dog
- Too low (base of the neck): The collar will be too loose and may slip off
Step 3: Pull Snug But Not Tight
Pull the tape measure until it’s snug against the skin. You should feel contact but not tension.
Do NOT pull tight — this will give you a falsely small measurement. Your dog should not resist or pull away.
For long-haired dogs, measure over the fur. Do NOT compress the fur. If you press down, the collar will be too tight once the fur settles.
Step 4: Read and Record the Measurement
Read the measurement where the end of the tape meets.
Write it down immediately. Do not trust your memory.
Double-check by measuring a second time. If the two measurements differ by more than 0.5 inches, measure a third time and take the average.
Step 5: Add 2 Inches for Comfort (The Golden Rule)
For most adult dogs, add 2 inches to the neck measurement. This gives room for comfort, fur, and slight weight gain.
Example: 16″ neck measurement → buy 18″ collar
Special cases:
- Dogs under 10 lbs: Add 1 inch (their necks are more delicate)
- Very thick-coated dogs: Add 2.5 inches
- Puppies: Add 2 inches, but check every 2 weeks
The Two-Finger Rule (How to Test Fit)
Measuring is step one. Testing the fit is step two. The two-finger rule is the gold standard veterinarians use.
What It Is
After putting the collar on your dog, you should be able to fit two fingers between the collar and your dog’s neck.
Why It Works
- Two fingers = snug but not tight = safe for the trachea
- Two fingers = secure against escape = can’t slip over the head
- Two fingers = room for fur and comfort = no collar burn
How to Test
- Put the collar on at your measured size
- Slide two fingers (index and middle) under the collar
- Fingers should slide in easily but not have extra space
Special Cases
- Small dogs (under 10 lbs): Use ONE finger (their necks are more delicate)
- Giant dogs (90+ lbs): Two fingers still applies
- Puppies: Two fingers, but check every 2 weeks
- Long-haired dogs: Two fingers, measured over the fur
“If you can’t fit two fingers, the collar is too tight — risk of collar burn and tracheal damage. If you can fit your whole hand, it’s too loose — escape risk. Two fingers is the sweet spot.” — Dr. Jackson
Dog Collar Size Chart by Breed
Important: These are approximate sizes. Always measure your individual dog. Breeds vary in size, and mixed breeds don’t fit neatly into categories.
| Collar Size | Neck Circumference | Example Breeds |
|---|---|---|
| XX-Small | 6″ – 8″ | Teacup Yorkie, Newborn puppy, Tiny Toy breeds |
| X-Small | 8″ – 12″ | Chihuahua, Yorkie, Maltese, Toy Poodle, Pomeranian |
| Small | 10″ – 14″ | Pug, Shih Tzu, French Bulldog, Boston Terrier, Miniature Schnauzer |
| Medium | 14″ – 18″ | Beagle, Corgi, Cavalier King Charles Spaniel, Scottish Terrier |
| Large | 16″ – 22″ | Labrador Retriever, German Shepherd, Golden Retriever, Boxer, Border Collie |
| X-Large | 20″ – 26″ | Rottweiler, Husky, Doberman Pinscher, Bernese Mountain Dog, Akita |
| XX-Large | 24″ – 30″ | Great Dane, Mastiff, Saint Bernard, Newfoundland, Irish Wolfhound |
Note on width: Collar width matters too! Narrow collars for small dogs (0.5″-0.75″), wider collars for large dogs (1.0″-1.5″). A wide collar on a small dog will rub and cause irritation.
Special Cases: Puppies and Long-Haired Dogs
Not every dog measures the same way. Here’s how to handle special cases.
Measuring Puppies (They Grow Fast)
Puppies need collars with extra room for growth — but they also need frequent re-checking.
- Measure and add 2 inches (same as adults)
- Check fit every 2 weeks — some puppies outgrow collars monthly
- Look for collars with wide adjustability (e.g., 8″ to 14″)
- Buy affordable collars during the rapid-growth phase (save premium collars for adulthood)
- Expect to buy 2-3 collars before your puppy reaches adult size
👉 See our guide: Best Training Collar for Puppies →
Measuring Long-Haired Dogs (Don’t Compress the Fur)
Long-haired breeds need special attention. If you compress the fur during measuring, the collar will be too tight once the fur settles.
- Measure over the fur — do NOT press down or compress
- For very thick coats (Huskies, Newfoundlands), add 2.5 inches instead of 2
- Consider rolled leather collars for long-haired breeds (prevents matting)
- Check fit more frequently — fur compresses over time
👉 See our guide: Best Leather Dog Collar (Rolled options) →
Measuring Between Seasons (Winter vs. Summer Coats)
Some breeds grow dramatically thicker winter coats.
- If your dog has a seasonal double coat (Husky, Golden Retriever, German Shepherd), measure in both summer and winter
- Use the larger measurement for year-round fit
- Consider having two collars — one for summer, one for winter
Common Measuring Mistakes (And How to Avoid Them)
Here are the five most common mistakes I see in practice — and exactly how to avoid them.
Mistake #1: Measuring at the Throat (Too Tight)
The throat is narrower than the middle of the neck. A collar measured at the throat will choke your dog.
Fix: Measure halfway between the ears and shoulders — NOT under the jaw.
Mistake #2: Pulling the Tape Too Tight
You want snug, not strangled. Pulling tight gives you a false measurement that’s too small.
Fix: Pull until the tape is snug against the skin without tension. You should be able to slide the tape without force.
Mistake #3: Forgetting to Add the 2 Inches
The neck measurement alone is the size of your dog’s neck, not the size of the collar you need.
Fix: Always add 2 inches before ordering. Write it on your hand if you have to.
Mistake #4: Measuring a Sitting or Lying Dog
The neck changes shape when sitting vs. standing. A sitting dog may have a different measurement.
Fix: Measure with your dog standing on all four paws.
Mistake #5: Ignoring the Width
A 1.5″ wide collar fits differently than a 0.5″ wide collar of the same length.
Fix: Consider width when sizing — wide collars feel tighter. When switching from narrow to wide, you may need to go up 0.5-1 inch.
When to Re-Measure Your Dog’s Neck (The Trigger List)
A collar that fit perfectly last month may be dangerous today. Re-measure your dog’s neck when any of these happen:
| Trigger | Why It Changes Fit |
|---|---|
| Weight change of 5+ lbs (up or down) | Significant body changes alter neck circumference |
| Seasonal coat change | Double-coated breeds grow thicker winter coats |
| Illness recovery | Dogs often lose weight during illness, then regain quickly |
| Post-surgery | Swelling can increase neck size temporarily; weight changes follow |
| Puppy growth spurt | Check every 2 weeks until 6 months old |
| Switching collar types | Leather fits differently than nylon; wide collars fit tighter than narrow |
| Senior dog body changes | Weight gain, loss, or muscle wasting changes neck shape |
| After starting a new medication | Some medications cause weight gain or fluid retention |
*”Most owners measure once and never think about it again. But dogs’ bodies change — sometimes gradually, sometimes overnight. The 8 triggers above should prompt an immediate re-measurement. Keep a soft tape measure in your dog’s grooming kit and check every 2-3 months even without triggers.”* — Dr. Allona Jackson, DVM
When in doubt, measure. A 30-second check can prevent collar burn or escape.
How Collar Width Affects Fit
Width matters just as much as length. Here’s why.
- A 1.5″ wide collar fits more snugly than a 0.5″ wide collar of the same length
- Wider collars distribute pressure over more surface area (good for large dogs)
- When switching from a narrow to wide collar, you may need to go up 0.5-1 inch
Width recommendations by dog size:
| Dog Size | Recommended Width | Why |
|---|---|---|
| Small (under 20 lbs) | 0.5″ – 0.8″ | Wide collars rub on short necks |
| Medium (20-50 lbs) | 0.8″ – 1.0″ | Good balance of comfort and control |
| Large (50-90 lbs) | 1.0″ – 1.5″ | Distributes pulling pressure |
| Giant (90+ lbs) | 1.5″ – 2.0″ | Maximum surface area for tracheal protection |
How to Measure for Special Collar Types
Different collar types sit at different positions on the neck. Here’s how to measure for each.
How to Measure for a Shock Collar (E-Collar)
Shock collars sit higher on the neck than standard collars — just below the ears.
- Measure at the high-neck position
- Contact points must touch skin (trim fur if needed)
- Snugger fit than standard collars
👉 See our guide: Best Shock Collar for Large Dogs →
How to Measure for a Bark Collar
Same as standard collars (middle of neck) — but fit is critical.
- Must be snug enough that sensors detect barking vibrations
- One-finger rule for dogs under 10 lbs
👉 See our guide: Best Bark Collar for Small Dogs →
How to Measure for a Leather Collar
Leather doesn’t stretch. Measure carefully.
- Add 2 inches exactly (not 1.5, not 2.5)
- Leather feels tighter than nylon of the same size
- When between sizes, size up
👉 See our guide: Best Leather Dog Collar →
How to Measure for a Nylon Collar
Nylon is more forgiving than leather.
- Add 2 inches (or 2.5 for thick coats)
- Nylon can be adjusted easily with multiple buckle holes
👉 See our guide: Best Nylon Dog Collar →
How to Measure for a Puppy Collar
Puppies grow fast — plan for it.
- Add 2 inches, but check every 2 weeks
- Buy adjustable collars with wide range (8″ to 14″)
- Expect to buy 2-3 collars before adulthood
👉 See our guide: Best Training Collar for Puppies →
FAQs About How to Measure Dog Collar Size
How tight should a dog collar be?
A properly fitted collar allows you to fit two fingers between the collar and your dog’s neck. If you can’t fit two fingers, it’s too tight. If you can fit your whole hand, it’s too loose. For dogs under 10 lbs, use one finger instead of two.
What size collar for a Labrador?
Most adult Labradors need a Large collar (16″ – 22″ neck circumference) with 1.0″ to 1.5″ width. But always measure your individual dog — some Labs are smaller or larger than average. Measure halfway between ears and shoulders and add 2 inches.
What size collar for a Golden Retriever?
Most adult Golden Retrievers need a Large collar (16″ – 22″ neck circumference). Goldens have thick fur, so measure over the fur (don’t compress it). Add 2.5 inches instead of 2 inches for very thick coats. Rolled leather collars help prevent matting.
How to measure a puppy for a collar?
Measure the same way as an adult (middle of neck, snug but not tight, add 2 inches). But check the fit every 2 weeks — puppies grow fast. Buy affordable, highly adjustable collars during the growth phase. Expect to buy 2-3 collars before your puppy reaches adult size.
Do I add inches for a rolled leather collar?
Yes — add 2 inches just like a flat collar. Rolled leather collars fit similarly to flat collars of the same length. However, because they’re round, they may feel slightly looser. If between sizes, size down for rolled leather.
My dog is between sizes — what should I do?
Always size up. A slightly loose collar can be tightened to the next hole. A too-tight collar can’t be loosened. Size up and use the adjustment holes to find the perfect fit.
How often should I check my dog’s collar fit?
Check the fit every month for adult dogs. Check every 2 weeks for puppies and senior dogs (who may gain or lose weight). Check after any significant weight change (illness, diet, seasonal coat changes, medication changes). See the “When to Re-Measure” trigger list above for 8 specific life events that require immediate re-measurement.
What if my dog’s measurements don’t match the size chart?
Size charts are guidelines, not rules. Go with your actual measurement (plus 2 inches). Different brands size differently. Always check the brand’s specific size chart before ordering. When in doubt, message the seller or size up.
Quick Reference: Printable Measuring Checklist
Copy this checklist or save it for your next measuring session.
- Soft fabric measuring tape (or string + ruler)
- Dog standing on all four paws
- Measure halfway between ears and shoulders (NOT throat)
- Snug but not tight against the skin
- Write down the measurement
- Add 2 inches (1 inch for dogs under 10 lbs)
- Test with two-finger rule (one finger for under 10 lbs)
- For long-haired dogs: Measure over fur, don’t compress
- For puppies: Check again in 2 weeks
Conclusion: Measure Once, Measure Right
A $10 tape measure saves you from buying the wrong collar — and more importantly, keeps your dog safe.
Here’s what to remember:
- Measure halfway between ears and shoulders
- Add 2 inches for comfort
- Test with the two-finger rule
- Re-measure when anything changes (see the trigger list above)
“A properly fitted collar is safer, more comfortable, and lasts longer. Don’t guess. Don’t estimate. Measure. It takes 60 seconds and could save your dog’s life.” — Dr. Allona Jackson, DVM.
Now that you know your dog’s size, explore our vet-reviewed collar guides:
- Pillar guide: Best Dog Collar (2026): The Ultimate Buying Guide for Every Dog →
- Specialty collars:
Related guides:
Disclaimer
The information provided in this article is for general informational and educational purposes only and does not constitute professional veterinary advice, diagnosis, or treatment. Always seek the advice of your veterinarian with any questions you may have regarding your pet’s health or collar fit.
Sources
- American Veterinary Medical Association (AVMA). “Collar Safety and Proper Fit Guidelines.”
- American Kennel Club (AKC). “How to Measure Your Dog for a Collar.”
- Pet Professional Guild. “Collar Fitting Guidelines for Pet Owners.”
This guide was reviewed for medical accuracy by Dr. Allona Jackson, DVM . Last updated: May 2026.
