Why cage size matters
Most cages sold in pet stores are far smaller than what welfare groups recommend. A small cage leads to boredom, weight gain, chewing on bars, fighting between cage mates and weak bones. The numbers below are minimums: bigger is always better.
Minimum cage sizes
| Animal | Floor space | Height | Notes |
|---|---|---|---|
| Guinea pigs (1-2) | 7.5 sq ft | 12 in | 10.5 sq ft for 3, 13 sq ft for 4 |
| Rabbits (pair) | 60 sq ft (10 × 6 ft) | 3 ft | Shelter plus run, open all day |
| Syrian hamster (1) | 775 sq in (100 × 50 cm) | 20 in | 8-10 in of bedding |
| Dwarf hamster (1) | 775 sq in (100 × 50 cm) | 16 in | Best kept alone |
| Gerbils (pair) | 775 sq in | 16 in | Tank or bin, deep bedding |
| Ferrets (1-2) | 6 sq ft | 3 ft | Plus 4 hours a day out |
| Chinchillas (1-2) | 6 sq ft | 3 ft | Tall, with wooden ledges |
| Hedgehog (1) | 4 sq ft | 18 in | 6 sq ft is better |
Worked example
Two guinea pigs need at least 7.5 sq ft. A typical pet store cage of 39 × 23 in is 39 × 23 ÷ 144 = 6.2 sq ft: too small. A 2 × 3 grid C&C cage (about 30 × 42 in, 8.75 sq ft) is enough, and a 2 × 4 grid gives room to add a third.
Cheap ways to get more space
- C&C cages (cubes and coroplast) are built from storage cube grids and a plastic base, and can be any size. They are the most popular choice for guinea pigs.
- Bin cages made from large clear storage bins work well for hamsters and gerbils.
- Exercise pens give rabbits and guinea pigs room to run indoors.
- Free-roam rooms work for rabbits once the room is rabbit-proofed.
Keeping rats? Use the rat cage calculator. Reptiles need the reptile tank size calculator.
Sources: Rabbit Welfare Association and Fund ("A Hutch is Not Enough"); Humane Society and guinea pig rescue guidance on C&C cage sizes; German TVT and RSPCA hamster and gerbil minimums (100 × 50 cm); American Ferret Association care guidance. These are minimum recommendations and some groups ask for more.
Frequently asked questions
How big should a guinea pig cage be?
At least 7.5 sq ft for one or two guinea pigs, 10.5 sq ft for three and 13 sq ft for four. A 2 × 3 grid C&C cage is the usual minimum for a pair.
How big should a rabbit enclosure be?
The Rabbit Welfare Association recommends at least 10 × 6 ft with a height of 3 ft for two rabbits, available all day. A hutch alone is not enough.
What is the minimum cage size for a hamster?
Many welfare groups now recommend at least 100 × 50 cm (about 40 × 20 in, or 775 sq in) of unbroken floor space for any hamster, with deep bedding.
How big should a ferret cage be?
At least about 36 × 24 in of floor and 36 in tall with several levels for one or two ferrets, plus at least 4 hours a day of free time outside the cage.
Can hamsters live together?
Syrian hamsters must live alone, and adults will fight. Dwarf hamsters are sometimes kept in pairs, but they often fight too, so most experts recommend keeping them alone.
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Last updated October 2026.