Open Litter Box for Large Cats: Find the Right Size

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We earn a commission from qualifying Amazon purchases made through links on this page, at no extra cost to you. Scores reflect specs and design fit for large cats.

⚡ Quick Verdict

📋 How We Evaluated

Each box was scored on interior length and width against the 1.5x sizing rule, wall height for scatter and spray, entry access for older cats, material and ease of cleaning and price against what you get. Dimensions come from the manufacturer listings and may change, so confirm them on the product page before you buy.

Dimensions	30″L x 20″W x 14″H
Entry Height	6.5 inches
Material	Smooth Plastic
Design Type	Open Top High Sided

What We Found

At 30 by 20 inches, this is the biggest pan in the roundup, and the extra length is the whole point. A big cat can turn, dig and stretch without a back foot hanging over the rim.

The 14-inch walls hold back most spray and dig-flinging, while the 6.5-inch entry cut keeps the box usable for a cat that isn’t a jumper. The interior is smooth plastic, which wipes clean faster than a textured pan. The open top vents ammonia between scoops, though it also means you can’t hide the smell from the room. Floor space is the price you pay: 30 inches is a lot of hallway.

Who It’s For

Owners of Maine Coons, Ragdolls and other long-bodied cats get the turning room they need. Cats that spray upward need the 14-inch walls to keep the baseboard dry.

Multi-cat homes can use the extra area to avoid territorial standoffs at the box. Senior cats with mild stiffness can step through the lowered front. Just don’t expect it to hide in a corner; it’s built for function.

Dimensions	30″L x 20″W x 14″H
Entry Type	Side Entry Curved
Color Option	Navy
Interior Finish	Smooth Easy-Clean

What We Found

Same 30 by 20 by 14 footprint as the top pick, with the opening moved to the side. That layout is sold as a way to cut litter tracking, and the 14-inch walls do the containment work either way.

The interior is smooth and easy to wipe, and the navy finish looks less like a utility tub than the usual gray. Airflow stays open. The catch is that cats used to stepping over a front rim sometimes need a few days to trust a side opening.

Who It’s For

Heavy trackers who still want a giant interior. Owners who care what the box looks like in a living room. Multi-cat homes that are tired of sweeping around the box every evening.

Giant breeds get the same 30 inches of length as the top pick.

Dimensions	19″L x 15″W x 11.75″H
Material	BPA-Free Recycled Plastic
Special Feature	Onboard Scoop Storage
Entry Style	Lowered Front

What We Found

This is the budget pick, made from BPA-free recycled plastic, with a lowered front and a spot to park the scoop. The 11.75-inch sides keep most scatter off the floor.

Here’s the honest part: at 19 inches long, it fits an average adult cat, not a giant breed. Under the 1.5x rule below, it suits a cat up to roughly 12.7 inches from nose to tail base. The build is basic, and there is no reinforced rim.

Who It’s For

Budget buyers who want a dependable pan without extras. Senior cat caregivers who need the lowered front. First-time owners who aren’t sure which style their cat will accept.

It also works as a backup or guest-room box.

Dimensions	19″L x 15″W x 11.75″H
Origin	Made in USA
Wall Height	11.75 inches
Style	Open Top Scatter Shield

What We Found

A made-in-USA tray with tall walls and an open top. The sides give some of the privacy of a hooded box without closing off airflow, and you can see at a glance whether your cat’s habits have changed.

It measures 19 by 15 inches, so it’s a mid-size box. It cuts floor cleanup compared with a low pan, but it’s too short for a Maine Coon.

Who It’s For

Cats that want more privacy than a flat pan gives but dislike hoods. Owners who need to monitor urine and stool for health reasons. Anyone who prefers US-made products.

Also a reasonable second box in a multi-pet home.

Dimensions	17.3″L x 13.4″W x 7.87″H
Material	Stainless Steel
Included Accessories	Scoop and Anti-Slip Pads
Surface Type	Non-Porous

What We Found

Stainless steel is non-porous, so urine can’t soak in the way it eventually does with scratched plastic. It’s the easiest box here to sanitize. The scoop and anti-slip pads are included.

But the walls are only 7.87 inches, lower than every plastic high-sided box above, and the 17.3-inch length limits it to small and medium cats. We include it because people searching for large-cat boxes keep landing on it. For a big cat, it’s the wrong size.

Who It’s For

Owners of small cats who are fed up with plastic that holds smell. Compact apartments where footprint matters more than interior volume.

Measure first. If your cat is bigger than about 11.5 inches nose to tail base, skip it.

Dimensions	14″L x 10.5″W
Target Size	Small/Kittens
Base Style	Wide Stabilizing Base
Edge Design	Rimmed for Lifting

What We Found

A small, plain open pan for kittens and tiny cats. The wide base keeps it from tipping, and the rimmed edge makes it easy to lift without sloshing litter.

At 14 inches long it fails the large-cat test outright. We list it so you know what not to buy. It works for a foster kitten, a quarantine setup or a travel box.

Petmate also makes a taller pan, covered in our Petmate open litter pan review.

Who It’s For

Kitten fosters who need a small, temporary box. Owners of very small adult cats. Travel and short-term use.

Skip it for any adult cat that is growing out of kitten size.

How to Size an Open Litter Box for a Large Cat?

Cat-behavior groups commonly recommend a box about 1.5 times as long as your cat from nose to the base of the tail. Most boxes sold as “large” do not meet that for an adult cat. Here’s how to check yours.

1. Stretch a soft tape measure from your cat’s nose to the base of its tail while it is standing.
2. Multiply that number by 1.5. That is your minimum interior length.
3. Check interior width. It should let the cat turn without touching a wall.
4. Confirm wall height. Aim for 12 to 14 inches if your cat sprays upward or digs hard.
5. Check entry height if your cat is a senior or has stiff joints.
6. Measure the floor spot, including the room to step around the box.

Litter Box Length by Cat Size

We calculated that last column from the listed dimensions. If your cat falls between sizes, round up.

Which Open Litter Box Should You Buy?

How to Cut Litter Scatter in an Open Box?

High walls do most of the work. A few habits finish the job.

• Keep litter about 2 to 3 inches deep. Deeper litter gets flung out faster.
• Put a large textured mat or tray under and in front of the box. Make it wider than the box.
• Use a heavier, low-dust litter for diggers. Light clumping litters travel further on paws.
• Place the box against a wall, not in the middle of a room. If your cat sprays, put a wall-side panel behind it.
• Scoop daily. A dirty box means more frantic digging and more mess.
• If tracking is the problem, try the side-entry version rather than a taller wall.

Cleaning an Open Litter Box and Controlling Odor

• Scoop at least once a day. Twice is better in multi-cat homes.
• Empty and wash the whole box every 2 to 4 weeks with mild, unscented dish soap and hot water. Rinse well.
• Skip strong cleaners, bleach and ammonia-based products. Cats avoid boxes that smell of them.
• Replace plastic when scratches pile up or odor stays after a wash. Scratches can harbor bacteria and smell.
• Let the box dry fully before you refill it.

A large cat produces large clumps. If you scoop less often than daily, the box will smell no matter what it is made from.

Can You Use a Storage Tub as a Large Litter Box?

Many owners of giant breeds do. A clear under-bed storage bin gives you 30 to 36 inches of length and tall walls for a small amount of money. It’s a decent test if you aren’t sure your cat will use a big box.

• Cut a smooth entry on one short side, about 6 to 7 inches high for most adults, lower for seniors.
• Sand the cut edge until it is not sharp. Cover it with a strip of smooth edge trim.
• Use plastic that is food-safe and unscented. Wash it before use.
• Replace it when it scratches or cracks. A cheap tub wears faster than a purpose-made box.

A purpose-made box is easier to clean and has safer edges. A tub is a workable fix, not a permanent answer. Dog pans are similar: they are big, but rarely have the high walls cats need.

What to Look For Before Buying?

Dimensions on the listing are the first thing to check. Marketing words like “jumbo” or “extra large” mean different things on different brands, so rely on the numbers.

For a step-by-step walkthrough that covers every cat size, see our guide on how to choose an open litter box.

Verify Interior Dimensions

Measure your cat from nose to tail base while standing, then multiply by 1.5. Compare it with the interior length, not the outside measurement, which includes the rim and feet. If the listing only gives one set of numbers, assume it is exterior.

Match Wall Height to Your Cat’s Habits and Mobility

Taller walls stop spray but make entry harder for older cats. Look for a lowered front or a cut-out. Twelve to 14 inches usually handles most high sprayers. If your cat is senior or arthritic, check the entry height and, if you can, test with a temporary ramp or step.

Compare Material, Durability and Odor Resistance

Stainless steel is non-porous and tough but usually costs more. Thick plastic resists scratches better than thin recycled plastic. Read reviews for long-term smell complaints, not just first-week impressions. Smooth finishes clean easier than textured ones.

Consider Placement and Tracking

Put the box away from noisy appliances and busy walkways. Leave room on all sides for airflow and for you to scoop. Side-entry boxes cut tracking near the box. In a multi-cat house, one big box per cat plus one extra is a common rule, and two mid-size boxes sometimes beat one giant one.

When a Large Cat Stops Using the Box?

A cat that suddenly goes outside the box is telling you something. A new box that is too tall, too small or in a new spot is one cause. Pain, urinary problems and stress are others.

• Straining, crying, frequent trips with little output, or blood in the urine: call a vet the same day. Male cats can get life-threatening blockages.
• A cat that goes just outside the box: try a lower entry, a bigger box, or a quieter spot.
• A cat that avoids a new box: put it beside the old one and move it gradually over a week or two.
• Keep one familiar box available while you switch.

This is general guidance, not a diagnosis. Your vet is the right person to rule out health problems.

Frequently Asked Questions

What size litter box does a large cat need?

Aim for a box about 1.5 times the length of your cat from nose to tail base. For a 20-inch cat, that is 30 inches. Width should let the cat turn without touching a wall. Measure your cat rather than trusting a “large” label.

What is the best open litter box for a Maine Coon?

Of the boxes here, the IRIS USA XX-Large High Sided is the best fit. It measures 30 x 20 x 14 inches, which meets the 1.5x rule for a cat up to 20 inches long. The side-entry version has the same footprint.

Are open litter boxes better than covered ones for large cats?

Often, yes. Open boxes give big cats more headroom and better airflow, and let you see their output at a glance. Covered boxes hide litter and can block some spray, but many are too short for large breeds.

Are high-sided boxes difficult for senior cats to enter?

They can be. Arthritic cats may struggle with tall walls. Pick a box with a lowered front or a cut-out entry, like the IRIS XX-Large (6.5-inch entry) or the Amazon Basics (lowered front), and watch how your cat steps in.

How do I stop a large cat from spraying over the sides?

Choose walls of 12 to 14 inches, place the box against a wall, and keep litter at 2 to 3 inches. If spraying is new or frequent, see a vet, because it can signal a health or stress problem. For more options, see our best open litter box for high sprayers.

How many litter boxes do I need for multiple large cats?

A common guideline is one box per cat plus one extra. With large cats, space the boxes out so one cat cannot guard them all. Our best open litter box for multiple cats guide covers setups for bigger households.

Does stainless steel really eliminate odors better than plastic?

It resists absorbing urine, which scratched plastic can do over time. It still needs daily scooping and regular washing. The stainless box in this roundup is small, so it only suits small cats.

How often should I replace a plastic litter box?

There is no set date. Replace it when deep scratches appear or when odor stays after a thorough wash. Heavy use in multi-cat homes wears boxes faster.

Can I use a large dog pan or storage tub as a cat litter box?

You can, but check the walls and edges. Dog pans often have low sides. A storage tub works if you cut a smooth entry and sand the edge. Purpose-made boxes are easier to clean and safer.

How deep should litter be in a large box?

About 2 to 3 inches suits most cats. Deeper litter gets kicked out faster and wastes product.

🎯 Final Verdict

Buy the IRIS USA XX-Large High Sided box if you own a giant breed. At 30 inches long with 14-inch walls, it is the one box here that meets the sizing rule for a Maine Coon-size cat. If tracking is your top complaint, the side-entry version has the same space and a different opening.

If your cat is average size, the Amazon Basics Large is the budget pick, especially for seniors. Whatever you choose, measure the cat and the floor first. A box that is too small gets ignored, and then you have bought it twice.

Want to compare more styles? Browse all of our open litter boxes, or start with our best indoor cat litter boxes guide.

📚 Related Guides

• Indoor Cat Litter Box: Complete Guide
• Open Litter Box: Complete Guide
• Best Open Litter Box for Multiple Cats
• Best Open Litter Box for High Sprayers
• How to Choose an Open Litter Box
• Petmate Open Litter Pan Review