Is my hamster cage too small?

Measure the inside of the cage base, multiply length by width, and compare the result to 775 square inches — the minimum PDSA publishes as 100 x 50cm. If you are under it, you are in the same position as most hamster owners, because almost every cage sold as a hamster cage is under it. The routes to fixing it start at the price of a storage tub.

If you have just discovered that the cage you bought in good faith is short of a published figure, this page is written for that moment. Nobody is going to tell you off here. Most people arrive at this subject having already bought a cage from a shop that sold it for this purpose, and that is a market problem rather than a personal failing.

How to measure, in two minutes

1. 1.Measure the inside of the base. Not the outside of the cage. On a wire cage the plastic base often tapers, so use the floor the animal walks on. The Prevue 528, for example, is 32.5 x 19 inches externally and 30 x 16 inches inside the base.
2. 2.Multiply. 30 x 16 = 480 square inches. That is the entire calculation.
3. 3.Add nothing. No shelves, no upper levels, no tube volume, no attached pods. Every published figure is about continuous, unbroken floor.
4. 4.Compare to 775. 480 is 62 percent. Now you know where you stand instead of how it looks.

Where common cages land

What the behavior tells you

Numbers aside, there are signs an enclosure is too small for the animal in it. None of these is diagnostic on its own, and together they are worth paying attention to:

• Persistent bar-chewing, particularly at the same spot and particularly at night. A hamster that chews bars for long stretches is usually trying to leave.
• Climbing the bars and dropping, repeatedly. This is a common stereotypy in undersized housing and it also carries a fall-injury risk.
• Pacing the same route, especially along one wall.
• Nesting where it toilets, or toileting in the nest. This is the clearest sign that the animal does not have enough separable areas.
• Rearranging the entire enclosure nightly. Some of this is normal; doing it every night to the whole floor usually means the floor is too small to settle.

What is not a sign: running on the wheel a lot. That is normal and healthy, and a hamster covers a remarkable distance overnight in any enclosure.

The options, cheapest first

Free: fix the bedding depth first

If your cage has a deep enough base to hold more substrate than it currently does, adding depth costs only bedding and is the single highest-value change available in an undersized enclosure. A hamster with six inches of substrate in a 480 square inch cage has meaningfully more usable environment than one with two inches, because the burrow adds a dimension the floor plan does not have. It does not fix the floor-area shortfall, and it is the best thing you can do this afternoon. See deep bedding.

Cheapest real fix: a storage tub

A large food-grade polypropylene tub with a mesh panel cut into the lid clears 775 square inches for less than most pet-store cages cost. It takes about an hour, needs a drill and a piece of hardware cloth, and the result is a better enclosure than anything in the table above. Full instructions, including the ventilation part people get wrong, in the bin cage guide.

Best floor per dollar: a DETOLF conversion

An IKEA DETOLF display cabinet laid on its back gives 1,086 square inches of continuous glass floor — 140 percent of the minimum — for a fraction of what a purpose-built enclosure of that size costs. The work is building a mesh lid, which is a genuine afternoon's project. Conversion guide.

Buy something that clears it

Three purpose-built enclosures do. They cost more than any of the above and require no work. Best hamster cages has the arithmetic for all of them.

What does not work

• Adding a second level. A platform is somewhere to sit. It creates no continuous floor and no published figure counts it.
• Adding tubes or another pod. Two undersized enclosures joined by a tube are two undersized enclosures. This is the most commonly suggested fix and it is the least effective.
• More toys and accessories. Enrichment inside a too-small floor plan takes up floor. Past a point, adding things makes the space problem worse.
• A bigger wheel alone. The wheel matters enormously — see wheel size — and in a small cage a compliant wheel takes a significant share of the floor. Do both, not one.

One last thing worth saying plainly. 775 square inches is a minimum published by veterinary charities, not a moral threshold, and the difference between 480 and 775 square inches is not the difference between cruelty and care. It is the difference between housing that meets a published standard and housing that does not, which is a real thing and a smaller thing than the tone of some of the internet would suggest. Getting there matters. Feeling terrible about the interval does not help the animal.