Choosing the Right Litter Box Size and Shape for Your Cat

A cat litter box should be large enough for the cat to enter, turn, dig and toilet without pressing against the walls. As a practical starting point, choose a tray at least one and a half times the cat’s length from nose to the base of the tail. Bigger is usually easier, provided the cat can enter safely and the tray fits in a suitable location.

Shape, wall height, lid and placement matter as much as the label on the box. The best tray is the one your cat can use comfortably and voluntarily, not necessarily the one that hides litter most neatly.

How to measure the right litter-box size

Measure your cat from the nose to the base of the tail while standing naturally, then multiply that length by 1.5. RSPCA Australia uses this as a starting point because many commercial trays do not allow enough room to turn, dig and squat.

For example, a 50 cm body length suggests a tray about 75 cm long. Width should let the cat turn without stepping out. Do not include a long fluffy tail in the measurement, and remember that external product dimensions can be larger than the usable internal floor.

If no standard pet tray is large enough, a smooth, sturdy storage container can sometimes be adapted. The plastic must be non-toxic, stable and free of sharp cut edges. Any altered doorway needs a smooth reinforced finish. Do not use a brittle box that can crack under the cat.

Open or covered litter box?

An open tray provides ventilation, a clear view and several directions to leave. It is also easier for an owner to see when cleaning is needed. This makes a large open tray a sensible first option.

A covered box may reduce visible scatter and offer privacy for an individual cat, but it can trap odour and restrict turning space. A timid cat may feel cornered if another animal waits outside the single entrance. The advertised outside size can also disguise a much smaller usable interior.

If you want to test a cover, offer an equally suitable open tray at the same time and compare voluntary use. Remove swinging flaps initially; some cats dislike pushing through them. Never force a cat into a covered tray or close the entrance.

Choose the entry height for the cat

High sides can contain spray and litter scatter, but the entry must remain accessible. Kittens, senior cats and cats with pain or reduced mobility often need a low doorway. International Cat Care’s home-modification guidance recommends a large tray with low access for cats with joint or mobility limitations.

A useful compromise is a large tray with high walls on three sides and a smooth low entry on the fourth. Place a non-slip mat beneath the tray so it does not move when the cat steps in. Avoid fabric or deep-ridged mats that trap urine and are difficult to clean.

Match shape to toileting behaviour

• Large rectangular open tray: a strong default because it maximises usable floor space.
• High-sided tray: may help a cat that urinates high against a wall or vigorously scatters litter.
• Low-entry tray: helps kittens, seniors and cats with reduced mobility.
• Covered tray: can suit an individual preference but needs generous interior space and ventilation.
• Top-entry box: may contain tracking but is unsuitable for many kittens, seniors, large cats or cats with mobility limitations.
• Corner tray: saves floor area but often provides less turning room than a rectangular tray.

Self-cleaning boxes also need enough usable room, a safe entry and a manual alternative. Follow weight and age restrictions, keep sensors clean and never use a cycle that frightens or risks trapping the cat.

How many trays do you need?

A common starting point is one tray per cat plus one extra, placed separately. Three trays beside one another do not provide three safe choices because another cat can guard the whole area. See how many litter boxes two cats need.

Even a single cat may prefer separate trays for urine and faeces. Multi-storey homes should have accessible options on each level the cat uses. Outdoor access does not remove the need for an indoor tray during bad weather, illness, curfews or neighbourhood conflict.

Placement can make a good box unusable

Cats Protection recommends quiet, accessible locations away from food, water, washing machines, busy doorways and cat flaps. A tray beside a noisy dryer may technically fit but still feel unsafe.

Provide more than one approach and exit in multi-cat homes. Avoid exposed glass doors where neighbourhood cats can stare in. In an apartment, a quiet bathroom corner may work if the door cannot accidentally close and the tray is not beside the food or water station.

Litter depth and liners

RSPCA Australia suggests starting with about 3–4 cm of unscented litter. Too little may prevent digging; very deep litter can feel unstable. Individual preference matters, so make gradual changes and offer a second tray when trialling a new material.

Avoid plastic liners that catch claws and move underfoot. Strong perfume, deodorising powders and harsh residual cleaning smells may discourage use. Our guide explains how often to scoop and replace litter, while another helps compare litter materials for sensitive paws.

Test preference without creating stress

Place two clean, appropriately sized trays in separate suitable locations. Change only one variable, such as covered versus open or high versus low entry, while keeping litter type and depth the same. Observe use for at least several days and keep the preferred tray available.

Do not repeatedly carry the cat to the tray. Make access easy, scoop frequently and let the cat choose. If a tray change follows surgery, pain or illness, ask the veterinarian about the safest temporary setup.

When a box problem may be a health problem

A sudden change in toileting warrants veterinary advice before it is treated as stubborn behaviour. Our overview covers why a cat may avoid the litter box, but it cannot diagnose urinary, digestive or mobility conditions.

Repeated straining, crying, frequent attempts with little or no urine, vomiting or weakness require urgent veterinary care. Urinary blockage can be life-threatening, particularly in male cats.

Quick buying checklist

• Internal length is at least 1.5 times the cat’s nose-to-tail-base length.
• The cat can turn and squat without touching every wall.
• Entry height suits current mobility.
• Walls contain scatter without creating a difficult doorway.
• The tray fits a quiet location away from food, water and appliances.
• Material is smooth, sturdy and easy to clean.
• Other cats cannot guard the only approach or exit.

Measure the cat first, then choose the location and shape. A generous, accessible tray is a small home-design decision that can prevent major stress. Browse more cat-friendly home setup guides for the surrounding environment.