Our jackets have generous adjustments to allow for different-shaped dog's bodies e.g. deep chests, broader shoulders or narrow bodies, and slim waists. The tapered shape of the jacket panels also helps to accommodate these better than 'square' jackets.

The only fixed measurement is the length of the spine so measure this as your starting point ( A to B on our diagram).

Measure from the front of the shoulders (A) to the base of the tail (B) as this is where the jacket will sit.

Your dog's weight gives an idea of whether they might need to go up or down a size if they are on or near the border of two sizes. Lighter frames err on the side of the smaller size; larger frames err on the side of the larger size if your dog is sitting on the border of two sizes.

We've also given some breed-shape reference points to help imagine the size of dog this item is suitable for. We've used well-known breeds so don't take it too literally, but imagine the size of your dog compared to these. Don't worry if they're taller or shorter in the legs, just the size of their torso is important (unless you want pants in which case we can't help you). For example, if you have a whippet-pointer-lab-spaniel supermutt that has ended up around the size of a Vizsla but with a scruffier face and shorter legs then go for the medium.