How Many Litter Boxes Do You Need? A Floor-Plan Guide for One, Two or Three Cats

By The Whisker Wilds Team. Updated November 2026.

How many litter boxes per cat? The common guideline is one box per cat, plus one extra: two boxes for one cat, three for two cats, four for three. According to the American Association of Feline Practitioners (AAFP) and the International Society of Feline Medicine (ISFM), the boxes belong in different spots, because cats treat boxes placed close together as one large box.

Cornell's Feline Health Center recommends the same number, but the formula is not based on hard evidence, as one UK source says plainly. We sell a cabinet that hides litter boxes; the cabinet section says what it changes and what it doesn't. We're not veterinarians; each fact links to its source.

Who recommends "one per cat, plus one," and how sure are they?

Why an extra box for one cat? Halls, a registered veterinary nurse, writes that cats outdoors "generally prefer separate locations for urination and defecation," so the ideal indoor setup is two trays for one cat. With several cats, Cornell says the extra box "decreases competition and gives each cat a box of his or her own."

How many litter boxes for 1, 2 or 3 cats?

The AAFP/ISFM handout opens its location advice with "Take a look at the floor plan of your home." None of the sources we read gives a distance in feet; the aim is that your cat sees separate boxes.

Two cats

Three boxes. In a one-bedroom apartment, that could be the bathroom, the bedroom and a quiet corner of the living area, all away from food and water.

Three cats

Four boxes. Avoid setting them out in pairs, which your cats may treat as two large boxes. Is three enough for three cats? Not by the guideline. Halls's social-group adjustment (next section) is something to try after watching your cats, not a shortcut.

Two floors

AAFP and ISFM advise a box on each level and, for an older cat, one on the level where it spends the most time. Battersea agrees.

Can cats share a litter box?

Some can. AAFP and ISFM describe "socially affiliated" cats, ones that groom, play or rest together, as cats that "may be more willing to share litter boxes." A home can hold more than one social group, and each group needs enough resources of its own.

For big households, Halls suggests a compromise: if the cats form one cohesive group, or clear sub-groups, the formula "can be adapted to 'one per social group plus one extra'."

So, can 2 cats share a litter box? A pair that grooms and naps together is the kind the handout means, but the guideline still says three boxes. Watch for one cat sitting near a box or blocking a hallway; the handout notes that a cat kept from the box may soil elsewhere. That's a reason to add a box in a separate spot.

Do two boxes next to each other count as two?

No. In the handout's words: "Keep the litter boxes apart in different locations because your cat considers boxes close to each other one large litter box." Halls adds that boxes in different areas make "strategic guarding by assertive individuals almost impossible."

Other placement points:

• Quiet and private, away from food and water (Cornell, AAFP/ISFM, Battersea).
• More than one way out. Cornell: "don't have the box surrounded on three sides." AAFP and ISFM warn against a closet or small room where another cat can block the exit.

How big should each litter box be?

AAFP and ISFM note that "many commercial litter boxes are too small" and that boxes "should be 1.5 times the length of the cat from the nose to the base of the tail." Battersea uses the same guide. Cornell adds that large and overweight cats "need bigger boxes," and that kittens, older cats and cats with mobility problems need low sides.

Measure your cat while it stands, from the tip of the nose to where the tail starts; do it twice and use the larger number. For the size rule, we compare 1.5 times that length with the inside floor of the box (our reading; the sources don't specify). For fitting furniture, use the box's outside length and width, rim and handles included.

Where does a litter box cabinet fit in?

We sell one in our litter box enclosures and furniture collection: our 47-inch double litter box cabinet. These numbers come from its product page (price as of November 2026):

What it does: it puts one or two boxes behind doors, and the top works as a side table. What it doesn't change:

The box count. Furniture holds boxes; the number still depends on your cats.

One spot, not two. The sources give no distance at which two boxes count as separate, so we count a two-box cabinet as one spot, whether it holds one box or two:

Most cats prefer an open box. Cornell puts it this way: "Most cats prefer an uncovered box that lets odors escape and allows a 360-degree view of their surroundings." An enclosed compartment works more like a covered box and is closed in on more than three sides. We haven't tested how cats use the center opening. A cabinet suits people who want a box out of sight; if your cat avoids the box once it's inside, move the box back into the open.

Size. A box fits if its outside measurements are under 16.9 in long and 16.4 in wide. Its inside floor is shorter than that, so by the 1.5 times rule it suits a cat measuring under about 11 in from nose to base of tail (16.9 ÷ 1.5 ≈ 11.3). Halls favors a "Jumbo" tray of 22 × 17 in as a minimum for multi-cat homes and large breeds, which is too long and too wide for these compartments. Measure your cat and your box before you buy.

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What if your cat starts going outside the box?

Take your cat to the vet. Cornell: "Cats who are having problems using the litter box consistently should be checked by a veterinarian." AAFP and ISFM add that every cat that starts to house-soil needs a thorough physical exam and a urine test, and Battersea says any change in toileting "should be checked by a vet." More boxes or new furniture don't replace that visit.

The short version

Count your cats, add one, and give each box its own spot on every floor your cat uses. A two-box cabinet counts as one of those spots.

We're not veterinarians. This guide is general information; ask your veterinarian about your cat.

Sources

All accessed November 2026.

• AAFP and ISFM, Feline House-Soiling: Useful Information for Cat Owners (owner handout, © 2014, sponsored by Ceva Animal Health)
• Cornell Feline Health Center, Feline Behavior Problems: House Soiling (updated January 2015)
• Battersea (UK), How to create the best litter tray setup for your cat (updated July 17, 2026)
• Cats Protection (UK), Vicky Halls, "To pee, or not to pee…", The Cat, Autumn 2013, pp. 24-25