Best Automatic Litter Box for Large Cats? A Size & Fit Guide

The right automatic litter box for large cats should give your cat enough room to enter, turn, dig, and use the litter comfortably. A bigger machine doesn't always mean a bigger litter area, so it's worth looking beyond exterior dimensions when comparing models.

For Maine Coons, Ragdolls, Norwegian Forest Cats, and other large-bodied cats, the most important considerations are usable litter space, entry height, freedom of movement, and the cat's individual habits.

So what makes an automatic litter box the best fit for a large cat? In this guide, we'll compare open-top and enclosed designs, explain the measurements that matter most, and look at real-life examples of large cats using the Popur S7 SLS.

How Much Space Does a Large Cat Need?

A large self-cleaning litter box needs to accommodate more than your cat's weight. Cats often turn around, dig, and adjust their posture before using the litter.

The AAFP/ISFM Guidelines for Diagnosing and Solving House-Soiling Behavior in Cats recommend a rectangular litter box approximately 1.5 times the cat's length from nose to the base of the tail.

This is a useful general guideline, but it isn't a strict body-length limit for every litter box design. Open-top litter boxes allow cats to position their heads and upper bodies beyond the tray's edges, rather than keeping their entire bodies inside an enclosed chamber.

Some cats may even keep their hind paws outside the tray while reaching in with their front paws to dig or cover litter. This flexibility is particularly relevant for larger, longer-bodied cats, although they should still have enough room to enter, turn, and eliminate comfortably.

Start by Measuring Your Cat

Measure your cat from its nose to the base of its tail, excluding the tail itself. Note its weight and overall build, too, but don't rely on weight alone to determine fit.

When comparing litter boxes, check what the advertised measurements actually describe:

• Exterior dimensions: The space occupied by the entire machine, including its motor housing or waste compartment.
• Litter tray dimensions: The length, width, and depth of the area where the cat eliminates.
• Diagonal length: The distance across the tray from one corner to the opposite corner.

What to Look for in the Best Automatic Litter Box for Large Cats

Before comparing features such as app controls or waste-bin capacity, consider how the litter box accommodates your cat's everyday movements.

Enough Room to Turn and Dig

Watch how your cat uses its current litter box. Can it turn without constantly brushing against the walls? Does it have enough space to dig and cover waste?

These behaviors can tell you more about comfort than a product's recommended weight range alone.

Headroom and Entry Access

Enclosed automatic litter boxes have fixed overhead clearance and internal chamber dimensions. For a particularly tall or long-bodied cat, those boundaries may make movement more difficult.

Open-top models remove the roof, but their litter trays still need to be large enough.

Entry height matters as well. A high step can be challenging for senior cats, short-legged cats, or cats with reduced mobility, even when the litter area itself is spacious.

Litter Depth and Waste Handling

Cats need adequate litter for digging and burying. Compare the tray depth with the recommended litter fill level rather than assuming the entire tray should be filled.

Also consider how the machine collects waste. Automatic cleaning is convenient, but it shouldn't come at the expense of a comfortable litter area.

Open-Top vs. Enclosed: Which Design Works Better for Large Cats?

Both designs can automate cleaning, but they offer different advantages.

For large cats that appear uncomfortable in confined chambers, an open-top layout may be worth considering. For others, a sufficiently spacious enclosed litter box may work just as well.

See the Space Difference

A larger-looking machine doesn't always mean more usable space for your cat. See how the Popur S7 SLS's open-top litter tray compares with an enclosed rotating-drum litter box.

The side-by-side comparison highlights the difference in headroom and surrounding clearance, giving you a clearer picture of how each design accommodates larger cats.

Is the Popur S7 SLS Suitable for Large Cats?

The Popur S7 Split Litter System (SLS) combines an open-top litter tray with an external, enclosed waste bin.

Unlike enclosed rotating-drum models, the S7 doesn't surround the cat with a chamber during normal litter box use. Its three-sided access allows cats to approach and position themselves with greater flexibility.

This is particularly relevant for larger cats whose heads or upper bodies may extend beyond the edges of the litter tray while they use it.

However, an open top doesn't increase the physical length or width of the tray. That's why the actual measurements are just as important as the design.

Popur S7 SLS Dimensions

What the Split Litter System Adds

Spaciousness is a key consideration in Popur's CARESS design philosophy, with the needs of large and long-bodied cats in mind from the start. The Popur S7 SLS puts this principle into practice through its Split Litter System (SLS), which pairs an open litter tray with a separate 11-liter waste bin. Rather than simply making the entire machine bigger, the design prioritizes freedom of movement where cats actually need it.

The S7 also retains the familiar shape of a traditional litter box, with an open top and no inward-sloping chamber walls to restrict movement. Its three-sided access gives larger, longer-bodied cats more flexibility to position themselves. They can turn, dig, or extend their upper bodies beyond the tray's edges without being confined by an enclosed chamber.

The deep litter bed accommodates up to 4 inches (10 cm) of litter, supporting cats' natural digging and burying behavior. And because the tray remains open and easily accessible, everyday tasks like topping up litter, checking cleanliness, and wiping down the surface are straightforward.

How to Check Whether the Popur S7 SLS Fits Your Cat

The most useful test is not whether your cat can stand inside the tray for a photograph. It's whether the cat can use it comfortably during a normal bathroom visit.

Pay attention to the following behaviors:

Cats that urinate high against the sides may benefit from additional splash protection. The S7 has an optional guardrail, but any accessory that raises the sides should also be evaluated for its effect on entry and exit.

For cats with significant mobility limitations, a larger low-entry litter box may be preferable to an automatic model with a higher step.

The goal is to find a setup your cat will use comfortably and consistently, not simply one that accommodates its weight.

See Large Cats Using the Popur S7 SLS

Watching large cats use the Popur S7 SLS in real-life situations can give you a better sense of the available space and how comfortably they move around. We've even seen a Maine Coon reported to measure 35 inches (88.9 cm) in overall length using the Popur S7 SLS.

The S7's spacious, open-top litter area has even accommodated two cats at the same time, as you can see in the video below.

These examples offer a helpful reference when evaluating whether the S7 might be a good fit for your own cat.

Frequently Asked Questions

Can a Maine Coon use an automatic litter box?

Yes, some Maine Coons can use automatic litter boxes comfortably. If you're choosing an automatic litter box for a Maine Coon, check the individual cat's body length, turning room, and entry accessibility rather than relying on breed or weight alone.

The same advice applies to Ragdolls and Norwegian Forest Cats.

Is a 24-inch litter box big enough for a large cat?

Yes, the Popur S7 SLS can accommodate many large cats, including Maine Coons and other long-bodied breeds.

The S7's 24.8-inch diagonal measurement describes its litter tray, not the maximum body length of a cat that can use it. Unlike enclosed rotating-drum litter boxes, its open-top design allows cats to extend beyond the tray's edges and adjust their posture more freely.

While the 1.5-times body-length guideline is a helpful starting point, actual fit also depends on how comfortably a cat can enter, turn, dig, and use the litter. Real-world examples of large cats using the S7 can provide a useful reference.

Are open-top automatic litter boxes better for big cats?

An open top removes overhead restrictions, which may help cats that dislike enclosed spaces. However, the litter surface must still provide enough room for the cat's normal movements.

What if my large cat has trouble entering an automatic litter box?

Check the entry height and observe whether your cat hesitates or struggles to step inside. A sturdy step or ramp may make entry and exit easier, especially for senior cats or those with limited mobility. Make sure any accessory is stable and suitable for your cat's needs.

Finding the Right Fit for Your Large Cat

Choosing an automatic litter box for large cats starts with understanding your cat's actual size and habits.

Compare usable litter space, headroom, entry height, and how the cat moves during a normal visit. A large exterior or an open-top design alone doesn't guarantee comfort.

The Popur S7 SLS offers an open litter area, three-sided access, and a separate waste collection system. For larger cats that benefit from unrestricted headroom, it's an option worth evaluating against their individual measurements and behavior.

Explore the Popur S7 Split Litter System for detailed dimensions, product features, and configuration options.