Choosing a cat litter tray seems like the most trivial aspect of owning a cat — and it is, in practice, the decision that prevents the most common problem of all: the cat refusing to use it. In most cases where this happens, the problem isn’t the cat. It’s the litter tray, the litter, or where it’s placed.
Size is where it often goes wrong
This is the number one mistake, and the easiest to fix. The litter tray should be at least about one and a half times the length of the cat, measured from the nose to the base of the tail. The cat must be able to get in, turn round completely, dig and cover its waste without touching the sides.
Most litters sold in shops are too small for an average-sized adult cat. If you’re unsure between two sizes, choose the larger one — I’ve never seen a cat complain about having too much space.
Open or closed?
The closed one suits us: it hides the view and contains the smell. But there are two things to consider from the cat’s perspective.
Firstly, a closed litter tray traps the odour inside — what’s pleasant for you is unpleasant for the cat that has to go in there. Secondly, many cats don’t like being unable to see whilst they’re vulnerable; in a household with more than one cat, a closed litter tray has only one exit, and that can be a problem if one of them tends to ambush the other.
If you do opt for a closed litter tray, make sure you keep it even cleaner. And if your cat has started refusing to use the tray after you’ve put the lid on, try taking it off — it’s one of the quickest fixes there is.
High sides, low entrance
These are different things, and both are important. High sides prevent litter from spilling out when your cat digs enthusiastically. A low entrance is essential for kittens, older cats or those with arthritis — if they have to jump to get in, sooner or later they’ll choose the carpet instead.
The ideal combination is a litter tray with high sides but a lowered entrance.
How many litter trays? The n+1 rule
The classic guideline in feline behaviour is one litter tray per cat, plus one. With one cat, two litter trays; with two cats, three. It may seem excessive, but it isn’t: it resolves most conflicts between cats and provides an alternative when one is dirty.
And, very importantly, don’t place them all side by side — to a cat, that counts as just one. Spread them out across different rooms, and in multi-storey homes, have one per floor.
Where to place them
- Away from food and water. No cat wants to eat next to the litter tray.
- In a quiet spot, but not so hidden that the cat has to go on an expedition — no locked-up storerooms or cellars.
- No dead ends. They must be able to see who is approaching and have a way out. Avoid tight corners.
- Away from washing machines or anything that makes a sudden noise. A fright whilst the machine is running might be enough to put them off going back there.
What type of litter to use
There’s no single answer, but there are practical differences:
- Clumping (bentonite) — forms solid clumps, which makes daily cleaning quick and allows you to remove only the soiled litter. It’s the favourite of most cats due to its fine texture, similar to natural sand.
- Silica (crystals) — highly absorbent and effective at controlling odours, meaning less frequent changes. Some cats find the texture and the sound when stepping on it strange.
- Plant-based (tofu, maize, wood) — biodegradable and lightweight, often flushable down the toilet depending on the manufacturer. They tend to be more expensive.
Two rules that apply to all types: put down a layer about 5 cm deep (any less than that and your cat won’t be able to cover their waste) and avoid strong scents — a cat’s sense of smell is much more sensitive than ours, and many instances of litter tray refusal start with scented litter. If you need to change the litter, make the transition by mixing the new litter with the old for a few days.
You can view our range of cat litter and hygiene products.
Is an automatic litter tray worth it?
An automatic litter tray sifts the litter by itself after each use and stores the waste in a sealed compartment. It’s particularly worthwhile in three situations: when no one is at home during the day, when there are several cats and the litter tray fills up quickly, or when daily cleaning is exactly what makes you put everything off.
What you should know beforehand: they’re larger and more expensive, they need to be plugged in, and some cats take a while to get used to the movement and noise — the transition should be gradual, keeping the old litter tray available for a few weeks. They’re not suitable for very young kittens. And ‘automatic’ doesn’t mean ‘maintenance-free’: you’ll still need to empty the tray and wash everything periodically.
If your cat starts going outside the litter tray
First, rule out a health problem. This is not optional and cannot wait. Urinary tract infections, crystals and blockages can change a cat’s behaviour overnight.
There is one situation that is an absolute emergency: a cat — especially a male — that repeatedly goes to the litter tray, strains, and produces no urine at all, or only a few drops, may have a urinary blockage. This is a condition that worsens within a few hours and can be fatal. Call the vet immediately.
Once you’ve ruled out any medical issues, go through the list: is the litter tray dirty? Is it too small? Have you changed the litter recently? Have you put a lid on it? Have you moved it to a different spot? Is there a new cat in the house, or are there building works or visitors? In most cases, the answer lies in one of these questions.
And never punish your cat for going outside the litter tray — they won’t understand the connection, and the stress will only make the problem worse.
Cleaning routine
Clearing away the waste once or twice a day is the bare minimum, and not just because of the smell: in the case of roundworms, the eggs passed in the faeces need weeks in the environment to become infectious, so removing them early breaks the cycle. We’ve explained this in detail in our article on roundworms in cats.
Wash the litter tray thoroughly on a regular basis, using water and a mild detergent. Avoid products containing ammonia — the smell is similar to urine and may encourage your cat to mark there. And wash your hands afterwards.
Sources
Informative content, revised in August 2026. This is not a substitute for a veterinary consultation.