Quick answer: A hidden litter box that cats still use needs an entry at least 18 to 20 cm wide at a comfortable height, room inside for the cat to turn and dig, some light, and airflow from a low intake to a high exhaust. Style the outside freely, but keep the inside plain, washable and roomy, and introduce it slowly alongside the old box.
Social media is full of beautiful litter cabinets. Some of them work, and some end up with a cat who refuses to go inside. The difference is usually in details the photos do not show: the entry, the inside space, light and smell.
This guide balances looks with what cats need. For more layouts, see our hidden litter box guide.
In a small flat, getting this right matters more, because the box is always close to where you live.
Start with the cat, not the furniture
Before choosing a cabinet, measure your cat from nose to base of tail and its height at the shoulder. Measure your current litter box and note how your cat uses it: does it dig hard, stand high, turn around several times or perch on the edge? A hidden box must give at least that much space. Many pretty cabinets are too small inside once the box is in, which forces the cat to crouch or hang its rear out of the box. Choose a cabinet that fits your cat and box first, then think about finishes.
Entry size and position
An entry around 18 to 20 cm wide and 20 to 22 cm tall suits most adult cats, with larger cats needing more. Rounded or arched openings look good and feel natural to cats. Place the entry on the side, so the cat walks in and turns toward the box, rather than stepping directly into litter. Keep the bottom edge low, especially for older cats. Avoid flaps at first; some cats accept them later, but many refuse them.
Space inside the cabinet
Leave room around the box: a few centimetres on each side and plenty above the cat's head when it stands. A cat that feels cramped may leave quickly or go elsewhere. If possible, leave a small landing zone between the entry and the box. This also forms an exit path that reduces tracked litter, as described in our litter tracking system.
Light and visibility
A completely dark cabinet can make cats nervous, especially in multi-cat homes where they like to see who is coming. A larger entry, a second small opening or slatted panels let in light. Some owners fit a small battery light inside, but keep it soft. Cats generally prefer to see out while they use the box.
Airflow keeps it acceptable
An enclosed box smells stronger inside than out. Cats have a far more sensitive sense of smell than people, so a cabinet that smells fine to you may be unpleasant to your cat. A low intake and a high exhaust, with a small fan and a carbon pad, keep the inside fresh. Our carbon filter guide covers fitting a filter, and our ventilation guide covers opening sizes.
Style the outside
This is where you can be creative. Paint the cabinet to match nearby furniture, add cane or rattan panels, change the handles, or use a plain finish with a wooden top. A shelf of books or a lamp on top makes it look like any other piece of furniture. Our guide to cat furniture that blends in has ideas for different styles. Keep anything that could fall away from the entry.
Keep the inside plain and washable
Inside, function matters. Seal wood with a waterproof finish, or line the floor with a removable plastic tray. Avoid fabric, carpet and wallpaper inside; they hold odour and are hard to clean. Plain light colours make it easier to see mess. The EPA brief guide to mold and moisture explains why damp surfaces in enclosed spaces need attention.
Placement in an apartment
Choose a quiet spot with easy access, away from food and water and not next to noisy appliances. A hallway, bathroom or corner of the living room often works in a small flat. Make sure the entry faces a clear space, not a wall a few centimetres away. Our placement guide covers how cats choose toilet spots.
Introduce it slowly
Put the new cabinet next to the old box with the doors open. Move some used litter into the new box. After a few days, close the doors but leave the entry open. Only remove the old box once your cat uses the new one reliably. The ASPCA guidance on litter box problems explains signs that a cat dislikes a box.
Signs your cat is unhappy
Watch for a cat that hesitates at the entry, leaves quickly, digs less, perches on the edge or goes just outside the cabinet. These suggest the space is too small, too dark or smells too strong. Act on them early, before the cat chooses a new spot in your flat.
Building versus buying
You can convert a second-hand sideboard, buy a flat-pack cabinet and adapt it, or buy a ready-made litter cabinet. A conversion gives the most control over entry size and interior space, which is the part most ready-made designs get wrong for large cats. A ready-made cabinet saves time but check the internal dimensions carefully against your box. Our flat-pack conversion guide covers the cutting and sealing steps if you go the DIY route. Whichever you choose, budget for a fan, carbon pads and a mat.
Cleaning without moving the cabinet
Design the cabinet so you can scoop without lifting it. A top that opens on hinges, or a front door that swings wide, gives easy access. A box on a pull-out tray slides forward for full litter changes. If cleaning is awkward, it tends to happen less often, which leads to odour and box avoidance. Keep a scoop and a sealed waste bin nearby, out of the cat's way.
Older cats and kittens
Older cats may struggle with a high entry or a step into the cabinet. Keep the entry low, and use a box with a low front. VCA guidance on arthritis in cats describes signs of joint pain. Kittens need a box they can climb into easily; a large cabinet with a shallow tray suits them while they grow.
Common design mistakes
The most common mistakes are an entry cut too small to look neat, a box pushed into a cabinet with no space around it, a front-facing entry that drops the cat straight into litter, no ventilation at all, and fabric or carpet lining inside. Another is choosing a cabinet so low that a tall cat cannot stand. Each of these can make a cat leave the box quickly or avoid it altogether. When in doubt, choose function over looks on the inside, and save the style for the outside panels, top and handles.
Making it quiet
Cats can be startled by a door that bangs or a cabinet that creaks as they step in. Fit soft-close hinges or felt pads on doors, and make sure the cabinet stands level so it does not rock. If you add a fan, choose a low-noise model and fit it with rubber washers. A calm, quiet box is more likely to be used, especially by nervous cats.
Check the cabinet's feet on hard floors as well. Rubber feet stop it sliding when a cat jumps in or out.
Checking it after a month
After a month, review how it is going. Is your cat using the box every day without hesitation? Is the inside dry and fresh? Is litter staying inside the cabinet? If any answer is no, adjust one thing at a time, such as a larger entry, more airflow or a bigger mat, and give it a week.
Hidden boxes in a home with two or more cats
In a multi-cat home, one cat may guard a cabinet with a single entry. A second entry or an open side helps. Provide more than one box in different locations. The AAFP/ISFM Environmental Needs Guidelines recommend separate litter areas for each cat.
FAQ: Aesthetic Hidden Litter Boxes
How big should a litter cabinet entry be?
Around 18 to 20 cm wide and 20 to 22 cm tall for most adult cats.
Do cats like enclosed litter boxes?
Many do if there is enough space, light and airflow.
Should I use a flap on the entry?
Not at first. Many cats refuse flaps.
What finish should I use inside?
A waterproof seal or a removable plastic tray.
How do I get my cat to use the new cabinet?
Introduce it slowly next to the old box, with some used litter inside.
Can I put the hidden box in a bathroom?
Yes, if the cat can always reach it and the door is never shut on them.
