What Size Cage Does a Budgie, Finch or Cockatiel Need?

Budgie on a wooden perch in a spacious cage

A budgie needs a cage at least 46 cm wide and long with bar gaps of about 9.5 mm, a finch or canary needs at least 60 x 40 x 45 cm with gaps of 0.8 to 1.2 cm, and a cockatiel needs at least 70 x 45 x 70 cm with gaps of 1.5 to 2.0 cm.^[1][2] Each of those is a minimum, not a target. Check three things before you buy.

Inside size: Measure the width, depth and height between the bars, not the size on the box, and compare each with the minimum for your species.
Bar spacing: Measure the gaps against the limit for your species, because spacing that is too wide can let a small bird escape or get its head stuck.^[2]
Wingspan rule: The RSPCA asks for a cage’s height, width and depth to be at least twice the bird’s wingspan if it spends most of its time inside, and one and a half times if it is mostly out.^[3]

The RSPCA also says a bird that lives in a cage needs at least six hours outside it every day.^[3]

What Does Cage Size Mean for a Budgie, Finch or Cockatiel?

Cage measuring 46 cm overall but 41 cm inside

Cage size is the usable space inside the bars.

Inside size, not box size: Trays and bases add to the outside measurement without adding space for the bird.
Bar spacing: Checked separately, because it is a safety measurement. Spacing that is too wide can let a small bird escape or get its head stuck,^[2] and a UK vet gives about 9.5 mm for budgies.^[1]
Shape counts as well as size: Most birds prefer rectangular cages to round ones, because they like having corners to sit in.^[4]
Bar direction counts too: Horizontal bars let a bird climb, which is why a UK vet recommends them for budgies.^[1]
Minimums are not targets: A UK vet calls 46 cm wide and long an absolute minimum for a budgie, and advises keeping birds in as large an enclosure as you can.^[1]

What Is the Minimum Cage Size for a Budgie, Finch or Cockatiel?

Minimum cage sizes for budgie, finch, canary and cockatiel

Each species needs a different minimum, so the table gives the cage size and bar spacing for each one.

Species	Minimum cage size (W x D x H)	Bar spacing
Budgie	At least 46 x 46 cm, height not stated ^[1]	About 9.5 mm ^[1]
Finch	60 x 40 x 45 cm ^[2]	0.8 to 1.2 cm ^[2]
Canary	60 x 40 x 45 cm ^[2]	0.8 to 1.2 cm ^[2]
Cockatiel	70 x 45 x 70 cm ^[2]	1.5 to 2.0 cm ^[2]

Note: Budgie sizing varies slightly between guides. A UK vet advises at least 46 cm of width and length with bar gaps of about 9.5 mm,^[1] while the Aosom lists 45 x 35 x 45 cm with gaps of 10 to 15 mm.^[2] The table above follows the vet, as it suggests the roomier cage and the narrower bar gap.

The full species table is on the Bird Cages page.^[2]

How Do You Check a Cage Before You Buy?

Hands measuring a bird cage with a tape measure

Three checks, in this order, show whether a cage works for your bird.

Check the inside size: Look for the inner space on the listing, because some listings give it separately from the overall size, as the worked example below does. If none is given, measure between the bars. Compare the width, depth and height with the minimum for your species in the table above.
Check the bar spacing: Compare the listed gap with the limit for your species. Check the gaps on doors and corners as well as the front panel, because a cage only has to fail in one place.
Apply the wingspan rule: Multiply your bird’s wingspan by one and a half or two, depending on how much time it spends in the cage, and compare the result with each inside dimension.

What Does the RSPCA Wingspan Rule Ask For?

The RSPCA bases the cage size on the bird’s own wingspan.^[3]

Mostly out of the cage: Height, width and depth should each be at least one and a half times the wingspan.
Mostly in the cage: Height, width and depth should each be at least twice the wingspan.
Birds kept together: Colony birds such as budgies, cockatiels and lovebirds need a cage at least twice the largest bird’s wingspan in every dimension.
More than two birds: For each bird beyond the first two, add 5 percent to the cage size for birds under 50 g, such as budgies, canaries and zebra finches, and 10 percent for birds of 50 to 100 g, such as cockatiels and lovebirds.
Space inside: The cage needs uncluttered room for a bird to flap its wings as often and as hard as it wants to.^[3]

The rule works on any bird you can measure. A bird with a 30 cm wingspan needs at least 45 cm in every direction if it is mostly out of the cage, and 60 cm in every direction if it is mostly in. Merck’s veterinary manual sets a similar test, asking for a cage at least one and a half times the bird’s wingspan in all directions, and bigger again for more than one bird.^[4]

So a cage can pass the size table above and still fail this rule, because the rule measures your own bird. A cage that fails is a short-stay cage, not a home.

How Does One 76 cm Cage Measure Up for Three Different Birds?

Budgies and canary inside a large black divider cage

The worked example below applies the three checks to one real cage. It is shown only to explain the method and is not a recommendation.

The PawHut Bird Cage with Divider is listed as suitable for finches, canaries, budgies and lovebirds ^[5], which makes it a fair test, because one label covers birds with different floors.

Specification	PawHut Bird Cage with Divider ^[5]
SKU	D10-106V00BK
Overall dimensions (L x W x H)	76 x 46 x 46 cm
Inner space (L x W x H)	76 x 46 x 41 cm
Bar spacing	1.2 cm
Material	Steel, PP
Included	4 perches, 4 food dishes, slide-out tray, built-in divider

Those figures work out differently for each bird.

Bird	Check 1: inside size	Check 2: bar spacing	Check 3: wingspan rule
Budgie	Passes. 76 x 46 cm clears the 46 x 46 cm minimum ^[1]	Wider than the vet’s 9.5 mm at 1.2 cm ^[1], though inside Aosom’s 1.0 to 1.5 cm range ^[2]	Passes for a bird mostly out of the cage with a wingspan of about 27 cm or less ^[3]
Finch	Fails on height. Length and width clear the 60 x 40 cm minimum, but 41 cm inside is 4 cm under the 45 cm minimum ^[2]	At the top of the 0.8 to 1.2 cm range ^[2]	Does not arise, since the cage is already under the height minimum
Cockatiel	Fails on height. Length and width clear the 70 x 45 cm minimum, but 41 cm inside is 29 cm under the 70 cm minimum ^[2]	Narrower than the 1.5 to 2.0 cm range ^[2], which is not a safety problem	Does not arise, since the cage is already under the height minimum

In practice, this means three things.

The cage is long and low: Its 76 cm length clears every length floor in the table, while its 41 cm inner height is under both the finch and cockatiel height floors.^[2]
The bar spacing needs a second look for budgies: At 1.2 cm it is wider than the UK vet’s 9.5 mm figure ^[1], although it falls inside the 1.0 to 1.5 cm range in the retailer’s budgie row.^[2]
The label is a starting point: The listing names budgies as suitable, and the cage does meet the budgie length and width floor, so for a budgie the open questions are the spacing and the wingspan check, not the label.^[5]

What Mistakes Make a Cage Look Bigger Than It Is?

These slips make a small cage read as a big one on a listing page.

Trusting the species label: One label can cover several species, and their floors differ, from 60 cm of length for a finch^[2] to at least 46 cm wide and long for a budgie.^[1]
Reading the box size as your bird’s space: The outside figure includes the tray and base. The cage in the worked example loses 5 cm of height before the bird gets any of it.
Judging by the table alone: The size table is only the first check. The wingspan rule measures your own bird, and it can ask for more than the table does.^[3][4]
Checking spacing in one place only: A front panel can pass while a gap at a door or corner fails.
Filling the cage: Perches and toys use the space you measured, and the RSPCA asks for a cage that is not too cluttered with toys so a bird can stretch and flap.^[3]

Bird Cage Size Checklist

Use this checklist on any cage, in the shop or on a listing, before the label gets a say.

What to check	Why it matters	Example
Inside length, width and height	This is the space the bird actually gets	41 cm inside against 46 cm overall on the worked example
Species floor	Each species has a different minimum	Budgie at least 46 cm wide and long ^[1]
Bar spacing	Spacing that is too wide can let a bird escape or get its head stuck ^[2]	About 9.5 mm for a budgie ^[1]
Wingspan rule	Measures the cage against your own bird	1.5 x wingspan if mostly out, 2 x if mostly in ^[3]
Room left after perches and toys	Fittings use the space you measured	A clear stretch for full wing flaps ^[3]
Number of birds	Groups need a bigger cage	Add 5 or 10 percent for each bird beyond two ^[3]
Time outside the cage	A cage is for short periods	At least six hours outside daily ^[3]

Choosing the Right Cage Size for Your Bird

The right cage size meets the minimum for your species, keeps the bar spacing within that species’ limit and still leaves room for full wing flaps once the perches and toys are in. Measure the inside, check the gaps in more than one place, then apply the RSPCA wingspan rule before trusting a label. Which measurement to check first depends on the bird.

Budgie: Height against the wingspan rule, and bar spacing against the figures above.^[1][3]
Finch or canary: Height and width against the species table.^[2]
Cockatiel: Height and depth against the species table.^[2]

FAQs

1. Is a Taller Cage Better Than a Wider One for a Cockatiel?

Neither on its own. A cockatiel cage needs enough length, depth and height to meet each floor, so check all three.^[2] Then apply the wingspan rule.^[3]

2. What Size Cage Do Two Budgies Need?

There is no single figure, because the rule measures the birds. The RSPCA asks for a cage at least twice the largest bird’s wingspan in height, width and depth for birds kept together,^[3] so double your largest budgie’s wingspan. Keep 46 cm as the minimum for width and length if the result comes out lower.^[1]

3. Does the Size on the Box Show the Space My Bird Gets?

No. Box figures are outside measurements, which can include the tray and base. Check whether the listing gives inner dimensions. If it does not, measure between the bars yourself.