Hamster housing, measured

Hamsters are the small pet most often housed in something too small, and the reason is structural rather than negligent: the cages sold as complete hamster kits cluster between 230 and 620 square inches of floor, and the lowest published minimum from a named veterinary body is 775. An owner who buys the largest cage in the shop, adds the wheel that came with it and fills it with the bedding on the same shelf has done everything the retail environment asked and still landed below every published figure.

So this section is organized around four numbers rather than around products. Floor area, bar spacing, bedding depth and wheel diameter. Get those four right and the rest is preference; get any of them wrong and no amount of accessories compensates.

The four figures, in the order they matter

Floor area comes first. 775 square inches of continuous, unbroken floor — PDSA's 100 x 50cm, published independently by Blue Cross, Wood Green and Germany's veterinary animal-welfare association. Continuous is the operative word: shelves, upper levels and tube volume do not count, because a hamster burrows downwards into substrate and there is no substrate on a shelf. Our hamster cage size guide shows how to measure the cage you own in about two minutes, and best hamster cages has the arithmetic for ten enclosures, three of which pass.

Bedding depth comes second, and is really the same figure in different units. PDSA asks for at least 25cm — ten inches. Ten inches of substrate in a 480 square inch base is not a burrow system, it is a deep box with one hole in it. This is also a hard physical constraint on cage choice: to hold ten inches of substrate you need solid walls to at least that height, which is why a wire cage with a four-inch base cannot do it however tall the wire above it is. See deep bedding for what ten inches means in liters, and best hamster bedding for which substrates hold a tunnel open.

Wheel diameter is third and is the cheapest thing to fix. PDSA publishes at least 30cm (12 inches) for a Syrian and 20cm (8 inches) for a dwarf, with a solid running surface rather than slats or bars. Nearly every wheel bundled with a cage fails both parts. Of five wheels we assessed, three clear the Syrian figure — the full comparison is in the safest hamster wheels, and the mechanics of why diameter matters are in hamster wheel size.

Bar spacing is fourth, and no welfare body publishes a figure for it. That leaves manufacturer specifications, which is exactly why our bar spacing guide works from published spacings rather than from rules of thumb. For a Syrian it is rarely the binding constraint. For a Roborovski it is the whole ballgame, and a cage whose spacing is not published is a cage you cannot assess before buying.

What decides price in this category

Not floor area, which is the useful and slightly annoying finding. The best-built wire cage we assessed — the Savic Hamster Heaven Metro, made in Belgium, heavy-gauge wire, 9.5mm spacing, a complete set of fittings — is 620 square inches, which is 20 percent short of the minimum. Meanwhile an IKEA display cabinet laid on its back gives 1,086 square inches for less money and no fittings at all.

What you pay for in this category is build quality, material and convenience. Floor area is nearly free, and the cheapest routes to it are a converted storage tub and a converted DETOLF cabinet. If budget is tight, that is genuinely good news: the thing that matters most costs least.

The mistake we see most

Adding rather than replacing. A 480 square inch cage with a second story added, or tubes attached, or a second cage connected through a tunnel, is still a 480 square inch cage. None of those additions creates continuous floor. It is an understandable instinct — you already own the cage, and adding feels like progress — and it does not move the number the published figures are about. Is my hamster cage too small works through what does help, including the options that cost nothing.

The second most common is treating the published minimum as a target. Every figure in this section is a floor: the level below which housing is inadequate. The bodies that issue them say so themselves. Clearing 775 square inches means you have got past the bar, not that you have done something remarkable, and the fuller discussion of which bodies publish what — including the widely repeated 450 square inch figure that no major welfare body appears to have issued — is on hamster welfare minimums.

Where to start depends on where you are. If you already have a hamster, measure the base of its cage and read cage size. If you are buying, start at best hamster cages and work out which side of the 775 line you are shopping on. If you have just discovered your cage is short, is my hamster cage too small is the page written for that moment, and it does not tell you off.