# Best Cat Litter Boxes (2026): Size, Covered vs Open, and Self-Cleaning > Seven open, hooded, top-entry and self-cleaning litter boxes, sized against the AAFP's 1.5-times-body-length rule, with Cornell's advice on covers and kittens. - Source: https://petprooflab.com/potty-cleaning/best-cat-litter-boxes - Publisher: PetProofLab (https://petprooflab.com) - Published: 2026-09-28 - Category: potty-cleaning - Tags: cat litter box, large litter box, covered litter box, top-entry litter box, self-cleaning litter box, kitten litter box, senior cat - Method: picks chosen from Amazon listings and brand specs; not hands-on tested; current Amazon prices are on the page; content checked 2026-09-28. - Quick answer: For most adult cats, buy a big open box: the IRIS USA XX-Large High Sided is 30 in long with a 6.5 in entrance, which covers the AAFP's advice that a box be at least 1.5 times the cat's body length. Cornell says most cats prefer an uncovered box, so pick a hood (Nature's Miracle) or a top-entry lid (IRIS or Modkat) only if your cat accepts it. Kittens and older cats need low sides, such as Petmate's small open pan. A self-cleaning box is a convenience, not a necessity: PetSafe says to leave its ScoopFree unplugged until a kitten is 6 months old. ## Key takeaways - Number: one box per cat, plus one, per Cornell, the ASPCA and the AAFP. - Size: the AAFP says cats prefer boxes at least 1.5 times the length of their bodies, and many commercial boxes are too small for larger cats. - Open beats covered for most cats, per Cornell; the ASPCA says most cats don't like lids or liners. - Kittens and older cats need low sides; the ASPCA warns that high sides or a top opening can make a box hard to get into. - Self-cleaning boxes have age and weight limits: PetSafe says unplugged until 6 months and best under 15 lb; Whisker says its Litter-Robot 4 scale does not detect kittens under 3 lb. ## Products (chosen from listings, not tested) 1. **IRIS USA XX-Large High Sided Cat Litter Box** (details: https://petprooflab.com/potty-cleaning/best-cat-litter-boxes#product-B0CVZRYCPW) — The biggest open box here, and the one most likely to pass the 1.5-times-body-length test for a large cat. - Pros: 30 x 20 x 14 in with a 6.5 in curved entrance, per the listing; Open top; IRIS pitches it at large breeds such as Maine Coons and at multi-cat homes; Sold by Amazon.com - Cons: At 30 in long it needs real floor space 2. **Amazon Basics Large Cat Litter Box with High Sides** (details: https://petprooflab.com/potty-cleaning/best-cat-litter-boxes#product-B0B7JKP75J) — A mid-size open box with a low front, for an average-size adult cat. - Pros: 19 x 15 x 11.75 in, open top, per the listing; Lowered front that the listing says makes it easier for older and large cats to get in and out; Scoop with on-board storage; sold by Amazon.com - Cons: 19 in long, so small for a big cat by the AAFP rule 3. **Petmate Basic Open Plastic Cat Litter Pan, Small** (details: https://petprooflab.com/potty-cleaning/best-cat-litter-boxes#product-B00L369CXQ) — The low-sided starter pan for a kitten's first weeks. - Pros: 14 x 10.5 in with 3.5 in sides, per the listing; Petmate says the small pan suits small cats or kittens; Sold by Amazon.com - Cons: A kitten will outgrow it 4. **Nature's Miracle Hooded Flip Top Cat Litter Box** (details: https://petprooflab.com/potty-cleaning/best-cat-litter-boxes#product-B01KBV4TL8) — A covered box for a cat that already uses one, or that sprays over open sides. - Pros: 25.13 x 19.13 x 11.75 in with a front entry, per the listing; Built-in charcoal filter and a flip-top front opening for scooping; Sold by Amazon.com - Cons: A hood holds odor in; Cornell says most cats prefer an uncovered box 5. **IRIS USA Large Top Entry Cat Litter Box** (details: https://petprooflab.com/potty-cleaning/best-cat-litter-boxes#product-B01MRV5YNO) — A low-cost top-entry box for a young, agile cat in a home with a dog. - Pros: 20.75 x 16.125 x 14.625 in with a 9 x 10.5 in top opening, per the listing; Grooved lid catches litter from paws; IRIS says the top entry also keeps dogs out; Made in USA; sold by Amazon.com - Cons: Top entry means jumping in and out, which the ASPCA flags as hard for some cats 6. **Modkat Top-Entry Cat Litter Box** (details: https://petprooflab.com/potty-cleaning/best-cat-litter-boxes#product-B004DBNGU8) — The design-first top-entry box, for an agile cat and an owner who hates tracked litter. - Pros: Top-entry lid doubles as a walk-off mat, per Modkat; Swivel lid for scooping; seamless full-height base; Reusable liner that Modkat says lasts up to 3 months; sold by Modkat - Cons: Same top-entry caveat as the IRIS, at a higher price 7. **PetSafe ScoopFree Crystal Pro Legacy Self-Cleaning Litter Box, Uncovered** (details: https://petprooflab.com/potty-cleaning/best-cat-litter-boxes#product-B07WZPJ2LW) — The self-cleaning pick for one or two adult cats under 15 lb, if you accept buying PetSafe's trays. - Pros: Rake sweeps waste into a covered trap 20 minutes after the cat leaves, per PetSafe's manual; Disposable crystal-litter trays; no daily scooping; Health counter tracks visits; sold by Amazon.com - Cons: PetSafe says it is best for cats under 15 lb and should stay unplugged until a kitten is 6 months old For most adult cats, the best litter box is a big, open one: the IRIS USA XX-Large High Sided is 30 inches long, which meets the American Association of Feline Practitioners' advice that a box be at least one and a half times the cat's length. Add a covered or top-entry box only if your cat accepts it, give kittens and older cats low sides, and treat a self-cleaning box as an optional extra with rules of its own. **How we chose:** we did not test these boxes; we checked each listing's dimensions against the AAFP and Cornell guidance below, and kept only boxes sold by Amazon.com or the brand's own store and in stock on September 28, 2026. ## Seven litter boxes side by side | Box | Type | Size (L x W x H, per listing) | Entry | Sold by | Amazon price | |---|---|---|---|---|---| | [IRIS USA XX-Large High Sided](https://petprooflab.com/potty-cleaning/best-cat-litter-boxes#product-B0CVZRYCPW) | Open, high sides | 30 x 20 x 14 in | 6.5 in curved front | Amazon.com | see the current Amazon price on the page | | [Amazon Basics Large High Sides](https://petprooflab.com/potty-cleaning/best-cat-litter-boxes#product-B0B7JKP75J) | Open, high sides | 19 x 15 x 11.75 in | Lowered front | Amazon.com | see the current Amazon price on the page | | [Petmate Basic Open Pan, Small](https://petprooflab.com/potty-cleaning/best-cat-litter-boxes#product-B00L369CXQ) | Open, low | 14 x 10.5 x 3.5 in | All sides | Amazon.com | see the current Amazon price on the page | | [Nature's Miracle Hooded Flip Top](https://petprooflab.com/potty-cleaning/best-cat-litter-boxes#product-B01KBV4TL8) | Hooded | 25.13 x 19.13 x 11.75 in | Front | Amazon.com | see the current Amazon price on the page | | [IRIS USA Large Top Entry](https://petprooflab.com/potty-cleaning/best-cat-litter-boxes#product-B01MRV5YNO) | Top entry | 20.75 x 16.125 x 14.625 in | 9 x 10.5 in top | Amazon.com | see the current Amazon price on the page | | [Modkat Top-Entry](https://petprooflab.com/potty-cleaning/best-cat-litter-boxes#product-B004DBNGU8) | Top entry | 15.9 x 15.9 x 14.6 in | Top | Modkat | see the current Amazon price on the page | | [PetSafe ScoopFree Crystal Pro Legacy](https://petprooflab.com/potty-cleaning/best-cat-litter-boxes#product-B07WZPJ2LW) | Self-cleaning, open | 27.6 x 19.1 x 6.2 in (per PetSafe) | Open top | Amazon.com | see the current Amazon price on the page | ## How many boxes, and how big Start with the count. Cornell's Feline Health Center, in its page on [house soiling](https://www.vet.cornell.edu/departments-centers-and-institutes/cornell-feline-health-center/health-information/feline-health-topics/feline-behavior-problems-house-soiling), says: "Provide as many boxes as there are cats in the house, plus one." The [ASPCA](https://www.aspca.org/pet-care/cat-care/common-cat-behavior-issues/litter-box-problems) gives the same rule, and so does the AAFP. Two cats means three boxes, ideally not side by side: the AAFP's client handout says boxes "should be placed in at least 2 different locations." Then size. The AAFP's [Feline Behavior Guidelines](https://catvets.com/wp-content/uploads/2024/01/FelineBehaviorGLS.pdf) say "cats prefer litter boxes that are at least 1.5 times the length of their bodies" and that "many commercial litter boxes are too small for larger cats." The same handout suggests sweater storage boxes, cement mixing tubs and small dog litter pans as alternatives. Cornell puts it more briefly: "Larger cats need bigger boxes." To use the rule, measure your cat from nose to the base of the tail and multiply by 1.5. A cat that measures 18 inches wants a box about 27 inches long. By that math the IRIS XX-Large (30 in) suits most adult cats, the Nature's Miracle hood (25 in) suits an average cat, and the Amazon Basics box (19 in) suits a smaller one. The Modkat Top-Entry is about 16 inches square per its listing, so it suits a smaller cat. For the PetSafe ScoopFree, weight is the limit: PetSafe's own manual says it is "best for cats under 15 lb." Litter depth matters too. The ASPCA says "most cats like a shallow bed of litter" and to use "one to two inches of litter rather than three to four inches." Our [cat litter guide](https://petprooflab.com/potty-cleaning/best-cat-litter) compares clay, silica, pine, wheat and tofu litters. ## Covered or open? Cornell is direct: "Most cats prefer an uncovered box that lets odors escape and allows a 360-degree view of their surroundings." The ASPCA adds that "most cats don't like box liners or lids on their boxes." A hood keeps the smell away from you, which is the point, but it also keeps it inside with the cat. That does not make a hooded box wrong. Some cats spray high or kick litter hard, and a hood or a high back stops both. If your cat already uses a covered box without trouble, the **Nature's Miracle Hooded Flip Top** has a charcoal filter and a front that flips up for scooping. If you are switching a cat from open to covered, try it next to the old box, not instead of it. **Top-entry boxes** solve two different problems: tracked litter and a dog that raids the box. The **IRIS Large Top Entry** has a grooved lid to catch litter, and IRIS says the top entry keeps other pets such as dogs out. The **Modkat Top-Entry** uses its lid as a walk-off mat and swivels open for scooping. Both ask the cat to jump in and climb out. The ASPCA warns that "boxes that have sides that are too high or have a top-side opening might make it difficult for your cat to enter or leave the box," so skip top entry for a kitten, a senior or a cat with stiff joints. With an open or front-entry box, a [litter mat](https://petprooflab.com/potty-cleaning/cat-litter-mats) where the cat steps out catches tracked litter instead. ## Boxes for kittens and older cats Cornell says "kittens and elderly cats need boxes with low sides," and the AAFP's guidelines tell owners of young kittens to "provide litter boxes with low sides for easy entry." For a kitten's first weeks, the **Petmate Basic Open Pan, Small** has 3.5 inch sides, and Petmate says it suits small cats or kittens. Move up to a full-size box as the kitten grows; our [new kitten checklist](https://petprooflab.com/life-stages/new-kitten-checklist) covers the rest of the first-day list. For an older cat, the AAFP says more and bigger boxes, cleaned often, help prevent accidents caused by dirty boxes, "decreased ability to get to or into the box," and disorientation. It also suggests night lights for cats with failing vision. The **Amazon Basics** box has a lowered front that its listing says helps older and large cats, and the **IRIS XX-Large** has a 6.5 inch entrance in a 14 inch wall. A cat that suddenly stops using its box may be ill, not fussy. Cornell says "any medical condition that interferes with a cat's normal urination or defecation behavior can cause litter box problems," and the ASPCA lists urinary tract infection, interstitial cystitis and bladder stones among the causes. If the change is sudden, or your cat strains or cries in the box, ask your vet ([more on that](https://petprooflab.com/about#veterinary)). Clean any accidents with an enzyme product; our [enzyme cleaner guide](https://petprooflab.com/potty-cleaning/enzyme-cleaners-pet-stains-odors) explains why. ## Self-cleaning boxes: the rules makers publish A self-cleaning box saves scooping, not judgment. The ASPCA says "many cats accept them readily," but "if you're using a self-cleaning litter box and your cat starts eliminating outside the box, try switching to a traditional type of litter box." You also lose the daily look at the clumps that tells you when something has changed, so check the app or the waste drawer. The makers set age and weight limits because their sensors need them: - **PetSafe ScoopFree.** The [Crystal Pro manual](https://www.petsafe.net/media/downloads/400-2352_scoopfree_second_generation.pdf) says: "If your kitten is under 6 months of age, leave the unit UNPLUGGED and scoop waste until kitten is 6 months old." It rakes "20 minutes after your cat leaves the litter box" and is "best for cats under 15 lb." PetSafe's [setup guide](https://support.petsafe.net/articles/how-to-set-up-my-petsafe-scoopfree-crystal-pro-self-cleaning-litter-box/) repeats the 6 month rule. - **Whisker Litter-Robot 4.** Whisker's [FAQ](https://www.litter-robot.com/support/article/litter-robot-4-frequently-asked-questions-faq/) says its SmartScale "will not recognize kittens that weigh less than 3 lbs (1.3 kg)," so those kittens "can use Litter-Robot 4, but not in automatic mode." So a kitten under the maker's minimum should not use a self-cleaning box in automatic mode. Leave it switched off and scoop by hand until the kitten passes the age or weight the maker names. We kept the **PetSafe ScoopFree Crystal Pro Legacy** because Amazon.com sells it. It uses disposable trays of crystal litter, and PetSafe says a tray keeps the box fresh for up to 30 days. We left out the **Litter-Robot 4**: on September 28, 2026 its Amazon listings were sold by Spreetail, not by Amazon.com or Whisker. ## Recalls None of these brands appears on our [pet product recall page](https://petprooflab.com/recalls), which tracks FDA and CPSC pet recalls from 2024 onward, and a search of the [CPSC recall database](https://www.cpsc.gov/Recalls) on September 28, 2026 found no recall of litter boxes, self-cleaning or otherwise. Check again before you buy a used self-cleaning box. ## Frequently Asked Questions ### How many litter boxes do I need for two cats? Three. Cornell, the ASPCA and the AAFP all say one box per cat plus one, and the AAFP says to put them in at least two different places. ### How big should a litter box be? At least 1.5 times your cat's body length, per the AAFP. Measure from nose to the base of the tail; an 18 inch cat needs a box about 27 inches long. ### Do cats prefer covered or uncovered litter boxes? Most prefer uncovered, according to Cornell, because odor escapes and they can see around them. A covered box is fine for a cat that already uses one. ### Can a kitten use a self-cleaning litter box? Only switched off until it reaches the maker's minimum. PetSafe says to leave the ScoopFree unplugged until 6 months; Whisker says the Litter-Robot 4 cannot detect kittens under 3 lb in automatic mode. --- *PetProofLab is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com. We did not test these litter boxes; sizes and features are the makers' own, from their listings and manuals. This guide is for general information and is not veterinary advice.* ## Sources - vet.cornell.edu: [Feline behavior problems house soiling](https://www.vet.cornell.edu/departments-centers-and-institutes/cornell-feline-health-center/health-information/feline-health-topics/feline-behavior-problems-house-soiling) - ASPCA: [Litter box problems](https://www.aspca.org/pet-care/cat-care/common-cat-behavior-issues/litter-box-problems) - American Association of Feline Practitioners: [Feline Behavior Guidelines](https://catvets.com/wp-content/uploads/2024/01/FelineBehaviorGLS.pdf) - petsafe.net: [Crystal Pro manual](https://www.petsafe.net/media/downloads/400-2352_scoopfree_second_generation.pdf) - support.petsafe.net: [Setup guide](https://support.petsafe.net/articles/how-to-set-up-my-petsafe-scoopfree-crystal-pro-self-cleaning-litter-box) - litter-robot.com: [FAQ](https://www.litter-robot.com/support/article/litter-robot-4-frequently-asked-questions-faq) - U.S. Consumer Product Safety Commission: [CPSC recall database](https://www.cpsc.gov/Recalls) --- Last updated: 2026-09-28 Canonical URL: https://petprooflab.com/potty-cleaning/best-cat-litter-boxes How to cite: "Best Cat Litter Boxes (2026): Size, Covered vs Open, and Self-Cleaning", PetProofLab, https://petprooflab.com/potty-cleaning/best-cat-litter-boxes (checked 2026-09-28). Disclosure: as an Amazon Associate PetProofLab earns from qualifying purchases. Safety information summarizes public guidance and is not medical advice.