A useful starting point
A commonly recommended starting point is one litter box per cat, plus one extra. That means two boxes for one cat, three for two cats and four for three cats. The number is a starting point, not the whole setup.
Placement matters as much as number
- Spread boxes across separate, quiet locations.
- Make sure a cat has more than one route to a resource where possible.
- Keep boxes accessible for kittens, seniors and cats with mobility limitations.
- Scoop regularly and notice which locations your cats actually prefer.
If accidents continue
Do not simply keep adding trays. Review box size, litter, cleanliness, location and social conflict, and speak with a veterinarian about a new or persistent toileting change.
Contact a veterinarian promptly for sudden, severe, persistent or worsening changes. Breathing difficulty, collapse, repeated straining to urinate, seizures or suspected poisoning can be emergencies. Online guidance cannot diagnose your cat.
Source and review note
This page uses Feline Veterinary Medical Association as a reference starting point. External organisations do not endorse this site.