How many litter boxes per cat do I need?

Your cats might not be counting, but nearly every cat expert on the planet is going to tell you that you need one more litter box than the number of cats in your house.

So, if you have one cat, you need two litter boxes. If you have two cats, you need three litter boxes.

You can do this simple algebra yourself: If you have nine cats, how many boxes do you need? Answer: 10. Nice job!

So, who are these litter-box experts? Actually, it's a pretty prestigious and trustworthy list:

• The American Animal Hospital Association[1]
• The Humane Society[2]
• The ASPCA.[3]
• The American Association of Feline Practitioners, and
• The International Society of Feline Medicine[4]
  
  

All of these cat-focused organizations agree that the ideal number of litter boxes is 1 + the number of cats in your household.

I can already hear some of you disagreeing:

Let me respond.

The litter box is an amazing agreement between cat and guardian

Cats are basically wild animals who live in our house.

We may call them domesticated, but they’re not really domesticated. Cats agreed to live near humans a few thousand years ago because we happened to be a good source of mice. But unlike other animals that we domesticated: sheep, dogs, cattle, to name a few, we didn’t do much to change cats. They did their mouse-catching thing, and we left them alone.

Cats who don’t live indoors, toilet where they want to. They might pee in your sandbox today, and your flowerpot tomorrow, and in the woods behind your neighborhood the next day.

In other words, the fact that we have convinced housecats to do their business in a 20- by 16-inch plastic box with some fake sand or pellets in it, is nothing short of a miracle.

Do not look a gift miracle in the mouth.

A cat who is using her litter box properly is something you don’t mess with

Just because you think you’ve given your cat everything he needs to toilet properly, does not mean your cat agrees. You might point out how nice the litter and litter boxes you’ve purchased are. You might insist that you clean your litter boxes thoroughly and frequently. You might be sure you’ve provided “enough” litter boxes to satisfy.

But if your cat isn’t happy with the litter-box arrangement in your house, for whatever seemingly illogical (to you) reason, no one is going to be happy.

In other words, it doesn’t matter what you think about how many litter boxes is the right number to have in your house. It only matters what the cats think.

Litter-box problems are a top reason that cats are relinquished to shelters

Cats who “eliminate inappropriately” are so difficult to live with that it’s one of the top five reasons cats are given up to shelters.[5]

Worse, 70% of cats in shelters are ultimately euthanized.[6]

For the sake of your cat, your sanity, and your carpet (not to mention your pillows, throw rugs, and clean laundry), do everything in your power to prevent a litter-box issue in your household.

An ounce of prevention, in this case, an extra litter box or two, is worth a pound of cure.

What is the logic behind the "1+" rule?

My daughter lived in an apartment with three roommates and one bathroom. The four people set up a morning-shower schedule, kept bathroom breaks short, and used deodorizer.

Cats are not like my daughter and her roommates. If something is “wrong” with the only available litter box, your cat might just decide to pee on your nice, soft bed instead. Once the “pleasure” of peeing on the bed has been established, it might be hard to convince her not to pee in the bed again in the future.

What are some of the things that could be "wrong" with the box?

• You moved the box four inches to the left.
• Another cat just used that box.
• Your cat is upstairs and the box is downstairs.
• The dog just walked by and sniffed the box.
• The box is in the bathroom and somebody closed the bathroom door for a minute.
• The resident cat bully in your household was standing near the box.
• Someone turned on the washing machine next to the box.

The beauty of “1 +” formula, is that there is always one more box for your cat to try.

So, hypothetically, there could be 15 cats in your house, all pooping at the exact same moment. But if you have 16 litter boxes, there is always an extra if one of the cats is unhappy with the only other box left.

But I only have one cat. Do I really need two litter boxes?

It’s true that having only one cat eliminates the multicat household drama around the litter box.

But just because there is no competition for the litter box, doesn’t mean your “only” doesn’t need an extra.

Science says that cats want a sparkling-clean litter box

One of my favorite, favorite, favorite studies about cats and litter boxes, shows that cats don’t like “obstructions,” as the scientists called them, in their litter box. Period.[7]

The scientists tried everything: they gave cats clean litter boxes and dirty litter boxes. They gave them litter boxes that were otherwise clean, but had just the scent of pee and poop. They gave them litter boxes that were clean but had fake pee and poop in them (plain water, and faux poop logs made of gelatin), which did not smell at all.

The cats wanted clean litter boxes.

They don’t want to see clumps and they don’t want to see lumps in their litter boxes, even completely odor-free fake lumps and clumps.

The scientists’ conclusion was that “obstructions,” including the fake pee and poop, get in the way of the cat performing her natural elimination sequence:

• A cat will sniff the area to be peed or pooped upon.
• A cat will dig at the litter to make a hole.
• A cat will do his business over the hole.
• A cat will smell his handiwork.
• A cat will bury the mess, possibly stopping to sniff again, before continuing to bury.

If, for example, you work late one night, and there is no one home to scoop the box, your cat may feel she has no other choice than to poop on the rug in the family room.

Hey, it was an emergency. Who could blame her?

Give her a second box.

But my cats don’t mind sharing litter boxes!

You might be right. In fact, science says you’re right.

The same study I quoted above says that cats who get along don’t mind sharing litter boxes. In fact, cats showed no preference for using a box that had their own pee or poop in it, versus a friend’s pee or poop.

Note that this study only looked at cats who were all spayed and neutered and got along great. This study did not include intact cats, cats who were strangers to each other, or cats who were aggressive toward each other.

So, your friendly cats might be getting along just fine with fewer litter boxes than the experts recommend, so long as you diligently clean, clean, clean.

But, if you’ve been a cat guardian for any length of time, you already know that it doesn’t take much to upset the apple cart. If one cat goes to the vet, for example, and comes home smelling like a stranger, all bets about the litter-box situation may be off.

Having enough litter boxes reduces the chance of a litter-box fail.

How do I know if the cats are unhappy with the current litter-box arrangement?

Your cats will let you know if something is amiss when it comes to their toilet. You just have to know what you’re looking at.

Eliminating outside the box. If a cat who normally uses the litter box suddenly starts peeing and pooping elsewhere, something is wrong. Contact your vet to rule out a medical problem first, and then read, “Why is my cat peeing on my bed?” to get to the bottom of it.

Leaving pee or poop uncovered. If a former burier suddenly stops burying, something might be amiss. Read, “Why doesn’t my cat cover or bury her poop?” and ask yourself if anything about the litter box or your household has recently changed.

Spraying the sides or wall around the box. A cat who suddenly starts spraying is trying to communicate something, usually with the intent of making himself feel safer and more secure. Spraying is most often a sign of anxiety.

Pay closer attention to any cat drama that may be going on in the house, and read, “Why do cats spray or mark with urine?” for more information.

Does it matter where I put the litter boxes?

(*Note: As an Amazon Associate, I may earn from qualifying purchases)

If you are going to have more than one litter box in your house, it matters very much where you put them.

Don’t put them all in one location, which is extremely tempting to do. Unfortunately, 10 litter boxes all lined up in the laundry room are the equivalent of one single, very large litter box from the point of view of cats. If all the boxes are in one location, it does not allow a cat, who may need more privacy, or may be getting stalked by another cat in the household, a chance to get away from it all to do her business.

There needs to be a litter box on every floor of the house. Some cats may be too old, or arthritic to run to the box downstairs if they’re upstairs, and other cats may simply say to themselves, “Why run all the way across the house and downstairs to that cold basement, when there’s a warm, fresh pile of clean laundry right here!”

Litter boxes need to be in “Goldilocks” locations. The spot should be well-ventilated, but not drafty. The spot shouldn’t be too hot or too cold. The spot should be private, but not at the end of a hallway or in a corner where a cat might feel trapped. Too much noise (such as near the furnace), or too much foot traffic (such as a frequently used bathroom) aren’t good choices either.

If you have a dog that is a bit too curious about the litter box, place it in a room protected by a baby gate, or install cat flap in the door, such as this simple Door Buddy, which keeps the door cracked open, the cat-shaped Kitty Pass Interior Cat Door which is adorable, but requires cutting, or this top-of-the-line “smart” door by PetSafe, which is microchip-based and only allows the “right” pet through the door.

Interested in other litter-box topics?

How to keep litter-box odor under control

How to litter train your new kitten

Why is my cat peeing on my bed?

How to get pee out of carpet

Why doesn’t my cat cover or bury her poop?

Why do cats spray or mark with urine?

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Dawn LaFontaine is a lifelong animal lover who always seems to have a little pet hair in her keyboard. Her blog, Kitty Contemplations, helps cat guardians better understand and care for the special beings they share their lives and homes with. Her cat-products business, Cat in the Box, sells beautiful, well-made, and award-winning products that she designed to meet the biological needs of cats.

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FOOTNOTES

[1] “General Litter Box Considerations.” AAHA, https://www.aaha.org/aaha-guidelines/life-stage-feline-2021/elimination/general-litter-box-considerations/.

[2] “How to Help Your Cat(s) Use the Litter Box.” The Humane Society of the United States, https://www.humanesociety.org/resources/how-help-your-cats-use-litter-box.

[3] “Litter Box Problems.” ASPCA, https://www.aspca.org/pet-care/cat-care/common-cat-behavior-issues/litter-box-problems.

[4] AAFP and ISFM Guidelines for Diagnosing and Solving ... - Sage Journals. Journal of Feline Medicine and Surgery, 2014, https://journals.sagepub.com/doi/10.1177/1098612X14539092.

[5] Dr. Marty Becker DVM | Mon Jun 10 07:30:00 EDT 2013. “5 Reasons Cats Are given up for Adoption and How to Avoid Problems.” Vetstreet, http://www.vetstreet.com/dr-marty-becker/5-reasons-cats-are-given-up-for-adoption-and-how-to-avoid-these-problems?page=2

[6] “Statistics.” National Kitten Coalition, 23 Dec. 2021, https://kittencoalition.org/news-events/statistics/.

[7] Ellis, J.J., et al. “Does Previous Use Affect Litter Box Appeal in Multi-Cat Households?” Behavioural Processes, Elsevier, 14 Feb. 2017, https://www.sciencedirect.com/science/article/pii/S0376635716302972#bib0125.