Bar spacing is the safety detail most buyers check last, and it is the one that causes the worst accidents. Bars too wide apart let a small bird squeeze its head through and get trapped, or let a tiny bird escape entirely. This free bird cage bar spacing chart gives safe spacing ranges by bird size, so you can check any cage with a ruler before you buy.
The ranges are narrow, and that is the point. Tiny birds like finches and canaries need spacing of 1.0 to 1.3 centimetres. Small birds like budgies and lovebirds need 1.3 to 1.6 centimetres. Medium birds like cockatiels and conures need 1.6 to 2.0 centimetres. Large birds like African greys and macaws need 2.0 to 2.5 centimetres. Each step up reflects a bigger head and a stronger body.
Using the tool is instant. Pick the size group that matches your bird and press Show safe spacing. You will see the range in centimetres plus a reminder to check every bar yourself. That reminder matters, because spacing can vary across one cage: doors, corners, and decorative sections sometimes have wider gaps than the main bars.
Measuring takes a minute and a ruler. Measure the clear gap between bars, not from the centre of one bar to the centre of the next, and check several places, including near doors and along the bottom. If any gap is wider than the safe range for your bird, the cage is unsafe for that bird, even if most of the bars are correct. One wide gap is enough for an accident.
The head test explains why the numbers are strict. A bird can pass its head through a gap that looks too small, because feathers compress and skulls are narrow. Once the head is through, the bird panics, twists, and can injure its neck or wings trying to pull back. Small birds can also squeeze their whole bodies through gaps that seem impossible, especially young or slim birds.
Second-hand cages need extra care. Older cages may have bent bars, rust, or repairs that widen gaps, and painted cages may hide damage under the coating. Check every bar for bending, run a finger along welds, and reject any cage with loose or sharp bars. A cheap second-hand cage that needs repairs is rarely a bargain once safety is counted.
Bar thickness matters alongside spacing. Large birds with strong beaks can bend thin bars, so macaws and cockatoos need thick, sturdy bars as well as correct spacing. Small birds need thinner bars they can grip with their feet. Match both spacing and thickness to the bird, and be suspicious of cages sold as suitable for all birds, since no one cage suits a finch and a macaw.
If you already own a cage with spacing slightly too wide, do not hope the bird will not test it. Birds test everything. Replace the cage, or house a larger bird in it and buy a correct cage for the small bird. Mesh panels sold to narrow gaps can help in some cases, but they must be fixed firmly, checked daily, and made of bird-safe material, not loose netting that can tangle toes.
Horizontal bars suit climbing birds better than vertical bars, because parrots and budgies climb by gripping with beak and feet. Vertical bars are fine for finches and canaries that hop and flutter rather than climb, but the spacing rule stays the same either way. Check that bar welds are smooth inside the cage, since rough welds can cut feet, and avoid cages with decorative scrollwork that creates traps for heads, toes, or leg rings.
This chart gives planning ranges for healthy adult birds of each size group, not a guarantee for every individual. Young, slim, or unusually small birds may need the lower end of their range. It is free, it needs no sign-up, and it runs entirely in your browser.