How to Choose the Right Litter Box: Size, Depth, and Hood Truths
The wrong litter box is a leading cause of cats toileting outside it. This guide covers the size, depth and hood decisions that actually matter — why bigger and open usually wins, how deep to fill, and when a covered box helps or backfires.
Quick answer
Buy the biggest open box that fits your space — at least one and a half times your cat's body length. Fill it with about 5 cm of litter, keep entry low for easy access, and skip the hood unless you have a specific reason. Most litter box problems come from a box that is too small, too shallow, or too enclosed for the cat's comfort.
The wrong litter box is a leading cause of cats toileting outside it.
Size: bigger almost always wins
Cats want room to turn around, dig and position themselves without touching the sides. A box that is too small is one of the most common reasons a cat starts going just outside it. Measure your cat from nose to the base of the tail and choose a box at least one and a half times that length. Many owners find a large plastic storage tub works better and costs less than a purpose-built tray.
Aim for a box at least one and a half times your cat's body length — most shop-bought boxes are too small.
Depth of litter: aim for about 5 cm
Cats need enough litter to dig a small hole and cover their waste, which is instinctive. Around 5 cm is a good target for most clumping litters. Too shallow and the cat scrapes the plastic and may stop covering; too deep and it spills over the sides and feels unstable underfoot. Keep the depth even and top up as scooping removes litter over the week.
Around 5 cm of litter lets a cat dig and cover without scattering it everywhere.
Entry height and accessibility
High sides help contain litter and scatter, but a tall entry is a barrier for kittens, seniors and cats with joint pain. If your cat is young, old or stiff, choose a box with at least one low side — under about 10 cm — or cut a lower entry into a storage tub. A cat that hesitates, hovers or half-climbs in may be struggling with the entry, not the litter.
The hood question: open vs covered
Owners often prefer covered boxes for looks and odour control, but many cats do not. Hoods trap ammonia smell and dust inside, reduce visibility (cats like to see approaching threats while toileting), and can feel cramped for larger cats. If you must use a hood — for a very messy digger, say — pick the largest one available and scoop it even more often. When in doubt, start open.
Placement basics
Even the perfect box fails in the wrong spot. Put it in a quiet, low-traffic area away from food and water, with an easy escape route so the cat is never cornered. In a small flat, avoid tucking it beside a noisy washing machine or in a cupboard the cat can be shut out of. Accessibility and calm matter as much as the box itself.
Quick FAQs
What size litter box is best? Bigger than you think — at least one and a half times your cat's body length. When in doubt, size up; almost no cat objects to too much room.
How much litter should I put in? Around 5 cm of even depth for clumping litters. Enough for the cat to dig and cover, topped up as scooping removes some over the week.
Are covered litter boxes bad? Not always, but many cats prefer open boxes. Covers trap odour and dust and reduce sight lines, so start open and only switch if your cat is happy with a hood.
Can I use a plastic storage box as a litter tray? Yes, and it is often better — larger, cheaper and easy to cut a low entry into. It is a popular fix for cats that need more room or a lower step-in.