Litter box too small? What size to choose for your cat
Plenty of cats abandon their usual litter box the moment a bigger one is placed next to it, a signal often mistaken for a simple whim. A study by Guy, Hopson and Vanderstichel, published in 2014 in the Journal of Veterinary Behavior, set up two differently sized boxes side by side for 74 cats across 43 households and found that most cats urinated more often in the larger box, well beyond the dimensions of most commercially sold litter boxes (research on Google Scholar). See more pointers in the accessories section.
Why does box size influence behavior so much?
A cat needs to be able to turn around, dig and squat without touching the walls; a box that's too short forces a cramped posture, sometimes even pushing the hind legs outside the box while urinating. This lack of space explains a share of out-of-box elimination cases, long wrongly blamed on a simple behavioral quirk.
What size should you actually aim for?
The usual rule of thumb sets a length of at least one and a half times the cat's body length, from the tip of the nose to the base of the tail, which is well beyond most standard boxes sold between 15 and 30 €. For an average-sized cat, that often means a box 60 to 70 cm (24 to 28 in) long, and more for a large breed like the Maine Coon.
How can you adapt existing gear without buying everything new?
- A plain plastic storage bin without a lid often offers more surface area than a box sold specifically as a cat litter tray
- Offering a second, larger box next to the old one, rather than removing it all at once, gives the cat time to compare and choose
- A bigger box also strengthens the case for getting the number of boxes right in multi-cat households
- Sizing up doesn't remove the need for daily cleaning, cleanliness remaining the second most decisive factor in regular box use
Our guide to choosing clumping litter rounds out these pointers on the substrate side.
Frequently asked questions
Can a box that's too big also be a problem?
Rarely, except for a kitten or a senior cat with fragile joints who struggles to climb over tall walls; a low, wide box is then preferable to a deep but narrow one.
Should you switch boxes as soon as avoidance starts?
A vet visit is worth doing first to rule out a medical cause, since box size is only one possible explanation among others for litter box avoidance.
Does the number of boxes matter as much as their size?
Yes, both factors combine: a large box doesn't replace the recommended number of boxes in a household with several cats.
This guide is part of Planète Pets’s Cats universe. Our advice is general in nature: for any health concern, your veterinarian remains the only reference.