X-Large: Golden Retriever, Rottweiler, Doberman Pincher, American Bulldog, other large-chested mixed breeds.
X-Large Long: (100-130 lbs. 5 inches added to length of XL) small Great Danes, Large Rhodesian Ridgebacks, smaller sized Mastiffs, Greyhounds, etc.
There are so many different sizes and shapes of dogs. We have done our best to offer suitable range of big dog apparel based on a sampling of several hundred dogs. Each size has a variance in girth of 4". Your dog may fall at the smaller end of the size, right in the middle, or on the upper limit. The jacket may be larger or smaller fitting on your dog depending where on the size range they fall. Even those dogs that are on the smaller size of a particular size, the fit is still suitable.
Measure the chest at its broadest point, which is usually 1-2" behind the front legs. The chest measurement must be an exact fit so it's important to be very accurate.
We recommend use of a fabric measuring tape when determining your pet's chest measurements. If you do not have one, use a piece of yarn or string and measure it up against a ruler.
Measure your pet from base of the neck to base of the tail. Again, because dogs come in all shapes and sizes, fit will vary greatly for each dog. As mentioned above, it is okay for your big dog's coat to be up to 7" shorter than it's actual length.