Practicable Reference Size of X-Large: L 3.74" x W 3.15". Lonsuneer soft dog boots are paw protectors for dogs, capable to protect paws indoor and outdoor. The boots are comfortable, flexible, lightweight and hand washable. Please measure across the whole paw pad to get the paw width and length. For these boots, a snug fit is better. If your dog's feet are in between 2 sizes and if you've chosen the larger one, you could kindly try to use socks for dog inside the boots and then the boots may fit and stay on better.