BuyCatnip / Litter box
Litter boxes: how many, how big, how clean
Most litter problems come down to too few boxes, boxes that are too small, or boxes that are not clean enough. Three numbers fix that.
How many boxes, and how big?
| Cat length (nose to tail base) | Box at least |
|---|---|
| 14 in (36 cm) | 21 in (53 cm) |
| 16 in (41 cm) | 24 in (61 cm) |
| 18 in (46 cm) | 27 in (69 cm) |
| 20 in (51 cm) | 30 in (76 cm) |
Boxes: one per cat plus one. One cat, two boxes; two cats, three boxes; three cats, four boxes.
Why size matters
Many boxes sold as standard are shorter than the rule above, especially for a large cat. A cat that cannot turn around comfortably may start going next to the box. If you cannot find a box long enough, a large storage tub with a low cut-out door does the same job.
A cleaning routine
- Every day: scoop out the waste.
- Every one to four weeks: empty the box, wash it with soap and hot water, and refill.
- About two inches of unscented clumping litter is enough.
Good to know
- Experts advise one litter box per cat plus one extra: two boxes for one cat, three for two cats.1,2,3,4
- A litter box should be about 1.5 times the length of the cat, measured from the nose to the base of the tail.2,3
- In preference studies, most cats chose a larger litter box than the ones usually found in homes.1,5,6
- Scoop the box at least once a day, and empty and wash the whole box with soap and hot water every one to four weeks.1,2,3,4
- Most cats prefer an unscented clumping litter.1,2,6
- About two inches of litter is enough; a deep bed is not needed.1,4
How we checked this page
Checked on October 20, 2026. We kept a fact only when two independent publishers agree, and each one is numbered to its sources below. Where sources give different numbers, we keep only what they share. We never write a price. This page was written with an AI assistant and checked against the sources below.
Sources
- Litter Box Problems, ASPCA
- Feline House-Soiling: Useful Information for Cat Owners, AAFP and ISFM
- Inappropriate Elimination in Cats, University of Illinois Veterinary Teaching Hospital
- A Guide To Litter Box Etiquette (2023), Texas A&M College of Veterinary Medicine
- Litterbox size preference in domestic cats (Guy et al., 2014), Journal of Veterinary Behavior (FAO AGRIS record)
- Litter box size and litter type preference in cats (Iwabuchi-Inoue et al., 2025), Journal of Veterinary Medical Science (J-STAGE)