A detailed size guie can be found in the photos.
Small - 60 cm x 50 cm - Toy & small breeds such as Miniature Dachshunds, Chihuahuas, Norfolk Terriers
Medium - 80 cm x 60m Small-medium breeds such as Standard Dachshunds, West Highland Terriers, Cocker Spaniels
Large - 100 cm x 80 cm - Medium-large breeds such as Springer Spaniels, Small Labrador, Whippets
XL - 117 cm x 85 cm - Larger Breeds such as Labrador, Golden Retriever, Rhodesian Ridgeback