Wire spacing is measured from the Center of one wire to the Center of the next wire (rather then the space inbetween)

For birds:

• 3/8" wire spacing is for extra small birds, including finches
• 1/2" wire spacing is for small birds including parakeets
• 5/8" wire spacing is for small-medium birds including lovebirds & parrotlets
• 3/4" wire spacing is for medium birds including cockatiels or conures
• 1" wire spacing is for Large birds including African Grays & Amazons
• 1+" wire spacing is for X-Large birds such as Cockatoos and Macaws

Animal Sizes are determined, for use in our website, by basic and generalized sizing.  These include X-Small, Small, Medium, Large, & X-Large. 

These are used as generalized sizes for all different types of pets, making it easy to refine what would be best suited for your pet.  If you are not sure how you might categories your pet, you can choose a range, or several different sizes, to try to refine your search.