In Great Britain, under the Control of Dogs Order 1992, dogs in public are required to wear a collar with the owner’s name and address, so a collar is more than just a walking accessory. It’s important to keep those details up to date as well as choosing a collar that fits properly.
A dog collar should fit securely enough to stay in place, but not so tightly that it feels restrictive. The exact fit depends on the collar style and your dog’s build, but the aim is the same: the collar should sit comfortably around the neck without slipping over the head or digging into the skin.
Getting the size right is key because even a well-made collar won’t work as intended if it’s too loose, too tight or simply the wrong proportion for the dog wearing it.
How Tight Should a Dog Collar Be?
A dog collar should feel secure without pressing tightly into the neck. As a general guide, the RSPCA recommends that you can comfortably fit two fingers between the collar and your dog’s neck, which gives you a useful starting point when checking the fit.
That said, every dog is different. A thick coat, loose skin or a broader neck can all affect how a collar sits, so it’s worth looking at the overall fit rather than relying on one rule alone. Once fastened, the collar should sit evenly and allow your dog to move naturally. It shouldn’t dig into the neck, leave obvious pressure marks or be loose enough to slip over the head.
How Do You Measure a Dog for a Collar?
The best way to choose a collar size is to measure your dog’s neck rather than relying on breed, weight or the size they usually wear. Use a soft tape measure and place it around the part of the neck where the collar would normally sit. Keep it comfortably close without pulling it tight, and if your dog has a particularly thick coat, try to measure through the fur rather than over a large amount of loose hair, as this can affect the result.
Once you have the neck measurement, compare it with the sizing information for the exact collar you are considering. Collar sizes aren’t universal, so a medium in one brand or range might cover a very different neck size from a medium in another. At Rogue Collars, for example, our Biothane, leather, tweed and tactical collars aren’t all sized in exactly the same way, which is why it’s always worth checking the individual product measurements before ordering.
It can be tempting to simply order the same size your dog usually wears, but the actual neck measurement is far more useful than the size label alone.
Does Collar Width Affect the Fit?
Yes, while neck circumference tells you whether a collar is long enough, the width affects how the collar feels on the dog. We offer different widths across our range, including 2.5cm, 3cm and 5cm Biothane dog collars, as well as fishtail and riot collars in our leather range.
A narrower collar might suit a smaller dog, while a wider option can look and feel more proportionate on a larger dog. Sometimes, specific designs are better suited to certain breeds too. For instance, a fishtail collar is a popular choice for greyhounds, lurchers and whippets, as it distributes pressure around their neck and prevents the collar from slipping when they pull.
Width shouldn’t be chosen purely for appearance, though. Think about your dog’s neck length and overall build. A very wide collar might be excessive on a shorter neck, while a very narrow design might not suit the proportions of a much larger dog. The goal is a collar that is balanced and sits comfortably.
How Can You Tell if a Dog Collar is Too Tight?
A collar that’s too tight will feel difficult to move around the neck or leave very little space between the collar and the skin. You may also notice rubbing, pressure marks, flattened fur or your dog appearing uncomfortable when the collar is touched or adjusted.
If your dog is still growing, has gained weight, or their coat has become noticeably thicker, a collar that once fitted well can also become too snug over time. You should be able to fasten and remove the collar without forcing it, and your dog should be able to move their head and neck normally while wearing it.
How Can You Tell if a Dog Collar is Too Loose?
A collar that’s too loose comes with its own problems. If it moves excessively around their neck, hangs down or can easily slip over the head, it might not provide the secure fit you need. Pay particular attention to dogs whose heads and necks are similar in width, as collars can sometimes slip more easily if they’re not adjusted correctly.
It’s also worth checking the fit once your dog starts moving. A collar that seems fine while they’re standing still can shift more than expected during a walk. Making sure collars and harnesses fit properly and remain in good condition is an important part of everyday safety and helps stop your dog from running away. The best approach is to aim for a fit that stays in position without feeling tight.
Should You Measure an Existing Collar Instead?
You can use an existing collar as a reference, but only if you know it fits correctly. If you do, lay the collar flat and measure from where the fastening sits to the hole or the position normally used. Even then, compare that measurement with the new product’s size guide rather than just ordering the same size as the collar’s label.
Different materials, fastening systems and collar widths can all affect how a new collar sits. For that reason, measuring your dog’s neck directly is usually the more reliable starting point.
When Should You Check Your Dog’s Collar Fit Again?
Don’t ignore dog collar sizing over time. Puppies grow quickly, adult dogs can gain or lose weight, and coat thickness can change throughout the year. A collar might also loosen slightly with everyday use, depending on its construction. For puppies in particular, it’s worth checking the fit regularly as they grow, because a collar that fit comfortably a few weeks ago can quickly become too tight.
We recommend checking the collar periodically, and whenever you notice a change in your dog’s body condition or how the collar sits. It’s also a good opportunity to check the fastening, hardware, and material. If anything is damaged or excessively worn, the collar might need replacing rather than readjusting.
Finding the Right Fit for Your Dog
The best-fitting dog collar should feel secure, comfortable and proportionate to the dog wearing it. Start by measuring their neck accurately, then compare that measurement with the sizing information for the specific product rather than relying on a generic small, medium or large label.
At Rogue Collars, our range includes different widths and sizing options across our Biothane, leather, tweed and tactical collars, so it’s worth checking each product individually before ordering. If your dog is between sizes or you’re unsure which option is right for them, take the time to double-check the measurements. A few minutes spent measuring properly can make a big difference to how comfortably and securely the collar fits in the long run.