What's the right minimum cage size for a cockatiel?

Shopping for a proper cage for Sunny and the options (and prices) are overwhelming. What's the actual minimum cage size for a cockatiel, and does bar spacing matter? Want to get this right the first time.

Bigger is always better, but the common minimum for one cockatiel is around 24"×24"×24", and crucially WIDTH matters more than height — they fly sideways, not up. Bar spacing should be about 1/2" to 5/8" so heads/feet can't get stuck.

Smart to get this right once. For a single cockatiel:

• Minimum size: roughly 24" × 24" × 24", but bigger is always better — and prioritize width over height, since cockatiels fly horizontally, not straight up.
• Bar spacing: about 1/2" to 5/8" — wide enough bars risk a head or leg getting stuck.
• Bar orientation: some horizontal bars give them climbing surfaces.
• Perches: swap out the single round dowel for varied-diameter natural-wood perches to protect foot health.
• Placement: against a wall (security), out of the kitchen, away from drafts and direct sun, in a room where the family spends time.

The cage is home base, but daily out-of-cage time still matters regardless of size. More on setup in best practices for parrot cage placement and creating safe play spaces for your parrot.

Get the biggest you can fit/afford. Horizontal space for movement, horizontal bars on at least part of the cage for climbing, and a couple of differently-sized natural perches (not just the dowel it comes with). Placement matters too — against a wall, not in a high-traffic doorway.