Once you’ve decided that a prong collar is the right tool for you and your dog, it can be confusing and challenging for dog owners to find the right fit. I’ve fit a vast variety of different dogs into prongs so I’m here to bring you the answer.

What link size of prong collar should you get? By far the biggest factor in finding the proper fit is the size of your dog. Here is a table showing all of the link sizes prongs come in and variables of dog size.

Link SizeNeck SizeDog WeightBreed Size
2.25mmup to 14in10 – 30 lbsSmall
3.00mmup to 18in30 – 60 lbsSmall or Medium
3.20mmup to 20in45 – 90 lbsMedium or Large
3.80mmup to 22in90 lbs and upLarge

While the size of your dog is the biggest factor, there are a few other things to consider when using a prong collar for dog training. To get a better idea of all of the variables, lets dive deeper into those link sizes.

A Detailed Look At Prong Collar Link Sizes

2.25mm – Small

This is the smallest gauge prong collar that is available for purchase. This is going to be the obvious first choice for smaller breeds, simply due to the lighter weight and smaller size. Chihuahuas, Pomeranian, dachshund, pug or any miniatures or toy breeds all do best with this size link.

However, that’s not its only use. Because you can always buy links to add length to the prong collar, you could make it long enough to fit a medium size dog.

The reason you would want to do that is if you a struggling to get an effective correction with the larger prong collars. Due to there being more “prongs per inch” in a smaller collar with added links, you will get a much more noticeable correction.

Be careful, I’ve seen some of these pop off while in use. It happens very rarely, but can possibly happen when you are least expecting it. It is almost certainly caused by the thinner gauge of the prongs.

When you pinch it on and off it is much easier to weaken and bend the prongs into a position that is simply not as secure as it should be. Just be careful about the amount of pressure you are using to take the collar on and off and you will be fine.

You should be backing up any prong collar with a second type of collar anyway. More on that later.

3.00mm – Small to Medium

This is the link size I find myself using most often. Even though there is some overlap with the next size up as far as weight of the dog you are trying to fit, I would rather add links to this 3.00mm one.

The reason for that is to create a much lighter collar than going up to the larger link size. That makes it much easier for your dog to get used to wearing it and much more comfortable for them in the end.

I’ve gotten great results with this collar on all types of medium breeds from bulldogs, dalmatians, greyhounds, retrievers and up to pitbulls, huskies and larger German shepherds.

I have never seen this collar fail or “pop off” like the smaller size, but you should definitely be playing it safe with every prong and back it up with another collar.

3.20mm – Medium to Large

The way I utilize this link size is to get that more “pinch for inch” for a better correction on a giant breed who isn’t responding to the largest link size.

Also, if even the giant breeds seem uncomfortable carrying the weight of the largest link size around, I will switch to this 3.20mm, adding links if necessary, and see how they respond. Often it is an improvement over the large size.

This link size is also where it starts to get a little difficult for a lot of people to pinch the links on and off. If you have issues with your hands like arthritis or are not very strong you might want to consider getting a version of this prong with a “quick release” on it.

3.80mm – Large

I reserve this largest link size only for those giant breeds that would be able to comfortably handle the weight of the collar. It is BIG and HEAVY. Most dogs just can’t wear it comfortably.

It is my go to for giant breeds like mastiffs, Great Danes, Great Pyrenees or Saint Bernard. Those are the dogs bred for carrying weight and the only ones that seem to be able to handle the largest prong link size in comfort.

Using this size can also be a real pain to find a fit that isn’t too tight or too loose, because of the size of the links. Removing or adding a single link to this size prong can easily make it no longer fit due to the large jump in link size.

Usually, your dog will be somewhere in between a whole link and you just have to accept the collar being a little tight or loose. Unless it is extremely loose and hanging a couple inches off the sternum like a necklace, I always error on the bigger side. You don’t a clear difference in having the prongs engaged and not.

Back Your Prong Up

As I stated earlier, in order to utilize the prong collar in the safest way, you should be backing up your prong collar with a different collar that has no mechanical action or chance of popping off – like a regular nylon collar, martingale or e collar.

The easiest way to go about doing this is with a regular carabiner. It doesn’t have to be a climbing carabiner that is rated to hold hundreds of pounds, the cheap ones work just as well. Either will work, but there won’t be a ton of force on the carabiner.

Put the carabiner on your back up collar, either through the d ring or on the collar itself, then clip it to the “dead” ring on your prong collar. This is the ring that you are NOT clipping your leash to.

This way, if your prong collar ever does pop off, your leash is still connected though that carabiner to your back up collar. So, you won’t lose your prong collar and – most importantly – your dog can’t run off.

Link Sizes and Prong Brands

Once you have determined which link size is going to fit your dog, you should not be purchasing just any brand of prong collar. A lot of cheaper brands that are found in retail pet stores are Chinese made from inferior steel and – the biggest issue – have sharp edges to the prongs!

Do NOT use a cheap collar with sharp edges! The prongs should be dull and rounded, not sharp.

The only brand really worth considering is the industry standard: Herm-Sprenger. Their collars are all made in Germany and produced well. I have fit hundreds of dogs to prong collars and have never felt a Herm-Sprenger prong with sharp edges.

In Conclusion

Collect some measurements on your dog and determine which link size of prong collar would be the best fit. Keep in mind that you can add or remove links to get the best fit and the smaller the link size, the more custom the fit.