What size cage does a guinea pig need? The Australian size guide
How much floor space guinea pigs really need, in square metres, by number of pigs. Based on RSPCA Australia guidance and international welfare standards.
If you remember one thing from this site, make it this: guinea pigs need much more floor space than most cages sold for them provide. They are ground-dwelling herd animals that run, “popcorn” (jump for joy) and patrol their territory. A cramped cage can lead to boredom, weight gain and squabbles between cage mates.
The short answer
For a pair of guinea pigs, aim for at least 1 m² of flat, continuous floor. That’s roughly a 2 × 4 grid C&C cage (about 71 × 142 cm).
RSPCA Australia recommends that a pair have an enclosure of at least 2 m × 0.5 m (10,000 cm²), at least 30 cm high, and rectangular rather than square so there is room to run.
Floor space by number of guinea pigs
The table below combines RSPCA Australia’s pair guidance with the widely used figures from Humane World for Animals (formerly the Humane Society of the United States), converted to metric.
| Guinea pigs | Bare minimum | Recommended | Example C&C layout |
|---|---|---|---|
| 1 | 0.7 m² | 1.0 m² (and find them a friend) | 2 × 4 grids |
| 2 | 0.7 m² | 1.0 m² | 2 × 4 grids (71 × 142 cm) |
| 3 | 1.0 m² | 1.2 m² | 2 × 5 grids (71 × 178 cm) |
| 4 | 1.2 m² | 1.5 m² | 2 × 6 grids (71 × 213 cm) |
| 5+ | +0.25 m² per pig | +0.3 m² per pig | 3-wide layouts |
Boars (males) generally do better with the larger figure, because extra room reduces territorial disputes. Our cage size calculator does this maths for you.
Only the flat, continuous, single-level floor. Lofts, ramps and shelves are nice extras for enrichment, but they don't count toward the minimum. Guinea pigs live on the ground, so height and levels don't make up for a small floor.
Why most pet-shop cages fall short
Many cages sold in Australian pet stores are labelled as suitable for guinea pigs but offer around 0.5 m² of floor, which is about half of what a pair needs. For example, a 101.5 × 51 cm rabbit cage gives only 0.52 m² of floor, less than the bare minimum for even one guinea pig.
A quick way to check any cage:
- Find the internal floor dimensions in centimetres. Product listings often quote external size, so allow a little less.
- Multiply length × width and divide by 10,000 to get m². For example, 120 × 60 cm = 7,200 cm² = 0.72 m².
- Compare that with the table above.
See how real products measure up in our researched picks.
Length matters more than height
Guinea pigs don’t climb like rats or chinchillas, so tall multi-storey cages mostly waste money. What they need is length to run. A long rectangle, such as 2 × 4 grids, is better than a square of the same area, because it gives a proper straight run and lets a less confident pig keep a polite distance from a bossy one.
Sides of 30 cm or more are enough for most guinea pigs. Add a lid if you have cats, dogs or small children.
Floor time is a bonus, not a substitute
Daily supervised floor time in a guinea-pig-proofed room is great enrichment. But the cage is where your pigs spend most of their life, including every night, so it needs to meet the size guidance by itself.
Next steps
- Use the size calculator for your exact group.
- Compare C&C cages, indoor cages and pens and outdoor hutches.
- Ready to set up? Follow our first cage setup checklist.
Want a properly sized cage without the DIY?
We're looking at bringing welfare-sized cages and C&C kits to Australia. Join the waitlist and tell us what you'd want.
This guide is general information to help you compare housing options. It isn't veterinary advice. If your guinea pig seems unwell, contact a vet experienced with exotic pets.
