Care guide · Hamsters

Hamster cage size: how big it really needs to be

Checked against PDSA: The ideal home for your hamster, Wood Green: Caring for hamsters, RSPCA: Hamster environment and 6 more on

A hamster cage should give at least 100 × 50 cm (about 40 × 20 in) of unbroken floor space, with sides tall enough to hold 25 cm (10 in) of bedding. UK welfare charities such as PDSA and Wood Green use that minimum for every species, Syrian or dwarf. Bigger is better, and floor space matters far more than height.

How big should a hamster's cage be?

At least 100 × 50 cm (40 × 20 in) of floor, measured inside the base, for one hamster. PDSA takes this figure from the Veterinary Association for Animal Welfare and adds that bigger is always better. Wood Green, the RSPCA Solent branch and the Bunny Jackpot Foundation rescue all give the same floor size.

That is a lot bigger than the cages most people picture. A hamster is small, but in the wild it runs long distances every night and digs burrows. The RSPCA notes wild hamsters can run up to five miles (8 km) a day. A cage has to hold a deep layer of bedding, a wheel big enough for a straight back, a sand bath, several hides and an open area to forage in, without any of them crowding the others.

If you are choosing a cage to buy, our guide to the best hamster cages covers which models reach this size.

What is the minimum cage size for a Syrian hamster?

100 × 50 cm (40 × 20 in) of floor and at least 50 cm (20 in) of height, according to Wood Green. Syrian (golden) hamsters are the biggest pet species at about 15 cm (6 in) long, so the minimum is truly a minimum for them. Wood Green adds that female Syrians may need more room still.

For a big Syrian, look for 120 × 60 cm (47 × 24 in) or more if you have the space. The extra width lets you give a full digging zone at one end and a feeding and sand area at the other, which is how wild hamsters split up their burrows.

What is the minimum hamster cage size in the UK?

There is no cage size written into UK law. The law gives owners a duty to meet a pet's needs, and the RSPCA reminds owners that this applies to hamsters. The figure UK charities and vets work to is 100 × 50 cm (40 × 20 in) of floor.

Older advice used smaller numbers, and you will still see them. Supreme Petfoods quotes Blue Cross guidance of 80 × 50 × 50 cm for Syrians and 60 × 30 × 30 cm for dwarfs. Many US pages, including PetMD, give 450 square inches of floor (about 2,900 cm²), and Humane World for Animals gives a 20-gallon tank. Those are all well under 100 × 50 cm, which is 5,000 cm² (775 square inches). We follow the larger UK figure, because it is the newest vet-led guidance and because a hamster with more room has more space to dig and fewer reasons to chew the bars.

Guidance Floor space In square cm
PDSA, Wood Green, RSPCA Solent (all species) 100 × 50 cm (40 × 20 in) 5,000 cm² (775 sq in)
Older Blue Cross figure, Syrian 80 × 50 cm (31 × 20 in) 4,000 cm² (620 sq in)
PetMD (US) 450 sq in About 2,900 cm²
Older Blue Cross figure, dwarf 60 × 30 cm (24 × 12 in) 1,800 cm² (279 sq in)

Do dwarf hamsters need a smaller cage?

No. Wood Green and the Bunny Jackpot Foundation both give the same 100 × 50 cm (40 × 20 in) floor for dwarfs as for Syrians. Only the height changes: Wood Green allows 40 cm (16 in) for Campbell's, winter white and Roborovski hamsters.

Small does not mean less active. Roborovskis are the smallest species, at about 3 to 5 cm (1 to 2 in) long according to Wood Green, and are also the fastest, and the Bunny Jackpot Foundation suggests their sand area alone should take up a third of the enclosure. We share our home with a dwarf hamster, so this is the size we work to as well. The real difference for a dwarf is the bar spacing: 7 mm (about ¼ in) or less, or they can squeeze out. If you are still deciding between the two, our Syrian or dwarf comparison sets them side by side.

Why floor space matters more than height

Hamsters live on and under the ground, so a wide, low cage suits them better than a tall one. PDSA recommends single-level cages over tall, multi-level ones, because hamsters have poor eyesight and can fall. The RSPCA warns that falls cause injuries, even from a few inches up.

  • Shelves and levels do not add floor. PetMD counts only continuous floor space, not shelves, levels or tubes.
  • Height is for bedding. The base must be deep enough for 25 cm (10 in) of bedding, which PDSA sets as the minimum. A cage with a 10 cm plastic tray cannot hold it.
  • Tubes and pods split the space. A cage made of small linked boxes may add up to 5,000 cm² but gives no single area big enough to dig in.

Deeper bedding is worth more than a second level. The Hamster Society Singapore reports that Syrians kept with 40 cm (16 in) or more of bedding chewed bars and wheel-raced less than those with shallow bedding.

Large hamster cages, tanks and bin cages compared

Any of these can work if it reaches 100 × 50 cm, holds deep bedding and has a secure, ventilated top. Here is how the main types compare.

Type Good for Watch for
Large wire-top cage with a deep base Good airflow, easy to reach in, light to move Base often too shallow for 25 cm (10 in) of bedding; bars can lead to bar chewing; check bar spacing for dwarfs
Glass tank (aquarium) with a mesh lid Holds very deep bedding, no bars to chew, easy to watch your hamster Heavy; a standard 40-gallon breeder tank is 91 × 46 cm (36 × 18 in), which is under the minimum; a 75-gallon is about 122 × 46 cm (48 × 18 in)
Wooden or glass-fronted "bin" style enclosure Very large floor for the money, deep bedding, quiet Bare wood must be sealed so urine does not soak in, and edges protected from chewing
DIY storage box ("bin cage") Cheap and deep Most boxes are under 100 × 50 cm; needs mesh panels for air; hamsters can chew soft plastic edges
Small "starter" cage with tubes Nothing for daily living Too small, multi-level, and hard to clean; best avoided

RSPCA advice prefers a solid floor to wire mesh, which can hurt feet, and says wooden cages should not be used unless protected. The Bunny Jackpot Foundation goes further and recommends barless enclosures only. Wood Green still lists bar spacing, so a well-sized barred cage with a deep base is a fair choice as long as your hamster is not chewing the bars.

How to measure a cage before you buy

  1. Find the inside base size. Shops often list the outside size, including the lid overhang. Take off 2 to 3 cm (1 in) each way if only outside sizes are given.
  2. Multiply length by width. You want 5,000 cm² (775 sq in) or more in one area, and neither side shorter than 50 cm (20 in).
  3. Check the base depth. The solid part of the base should hold 25 cm (10 in) of bedding without it spilling through the bars.
  4. Check the height for the wheel. A 30 cm (12 in) wheel on a platform needs more than 40 cm (16 in) of headroom.
  5. Check the bars and lid. Bars 1 cm (0.4 in) apart for Syrians and 7 mm (¼ in) for dwarfs, and a lid or doors that close firmly. PDSA calls hamsters escape artists.

What size wheel fits in a large hamster cage?

A 30 cm (12 in) wheel for a Syrian and a 20 cm (8 in) wheel for a dwarf, with a solid running surface, according to PDSA. Wood Green gives the same sizes. Your hamster's back should stay straight while it runs; an arched back means the wheel is too small. Our hamster wheel size guide has the detail for each species, and a wheel this size is one more reason the cage needs room.

Large hamster cages at Pets at Home and other shops: what to check

A label saying "large" or "extra large" does not tell you the floor size. Check the numbers on any cage, from any shop, against this list.

  • Inside floor at least 100 × 50 cm (40 × 20 in)
  • One main floor, not linked pods or tall towers
  • A deep solid base, or sides you can add to, for 25 cm (10 in) of bedding
  • Bars 1 cm apart for Syrians, 7 mm for dwarfs, or no bars
  • Room for a 30 cm (12 in) or 20 cm (8 in) wheel
  • A solid floor, not wire mesh
  • A secure lid or doors
  • Good airflow through mesh, not a sealed box

Once you have the right size, our hamster cage setup guide shows how to lay it out, and our guide to safe hamster bedding covers what to fill it with. For everything else, start at our complete hamster care guide.

Hamster cage size questions

Is 80 × 50 cm big enough for a hamster?

It is the older UK minimum for Syrians, and many cages are still sold at that size. Current guidance from PDSA and Wood Green is 100 × 50 cm (40 × 20 in) for every species. If you already have an 80 × 50 cm cage, give the deepest bedding it can hold and plan to upgrade when you can.

Is a 40-gallon tank big enough for a hamster?

A standard 40-gallon breeder tank is about 91 × 46 cm (36 × 18 in), so it falls a little short of the 100 × 50 cm UK minimum. It is far better than a small starter cage. A 75-gallon tank, at roughly 122 × 46 cm (48 × 18 in), gives more length, though it is still narrow.

Can a hamster cage be too big?

No welfare charity sets an upper limit, and PDSA says bigger is always better. A very large cage just needs more hides and plenty of scattered cover, so your hamster always has somewhere to dive into. Open, empty space with nowhere to hide can make a hamster nervous.

Do hamsters need tall cages?

They need height for bedding, not for climbing. PDSA prefers single-level cages because hamsters see poorly and can fall. Aim for 50 cm (20 in) of height for a Syrian and 40 cm (16 in) for a dwarf, most of it filled with bedding.

Can two hamsters share a large cage?

No. Wood Green advises keeping every species alone, because hamsters kept together often fight and can badly injure or kill each other. Syrians are solitary by nature. A bigger cage does not stop fights.

Why does my hamster chew the cage bars?

Bar chewing often means the cage is too small or the bedding too shallow. The Hamster Society Singapore reports less bar chewing in Syrians kept with 40 cm (16 in) or more of bedding. More floor, deeper bedding and more to forage usually help.

Sources

Read next

Best hamster cages: what to buy and what to skip

Buy a cage with at least 100 × 50 cm (40 × 20 in) of single-level floor, a deep base for 25 cm (10 in) of bedding and the right bar spacing.

Hamster cage setup: layouts and ideas that work

A cage of at least 100 x 50 cm with 25 cm of bedding, a buried hide, a solid wheel, a sand bath, a dig box and scattered food.

Best bedding for hamsters: what is safe and what to avoid

Unscented paper bedding, alone or mixed with aspen or hemp, at least 25 cm (10 in) deep. Skip sawdust, pine, cedar, scented and fluffy bedding.

Hamster wheel size: what each species needs

Syrian and Chinese hamsters need a solid wheel of at least 28 to 30 cm (11 to 12 in); dwarfs and Roborovskis at least 20 to 21 cm (8 in).

Hamster care: the complete guide

A hamster needs a cage of at least 100 x 50 cm, 25 cm of bedding, a solid wheel, a measured dry diet with fresh veg, a quiet room and a life alone.

Syrian or dwarf hamster: which should you get?

A Syrian is bigger, calmer and easier to handle; dwarfs are smaller, faster and best watched. Both need a 100 × 50 cm (40 × 20 in) cage.