Litter box size guide: why most store-bought boxes are too small
The AAFP/ISFM guidelines say "size of the litter box is as important as the number of boxes. In general, bigger is better."
The measurement
Measure your cat from nose to base of tail and multiply by 1.5. That is the recommended box length. In one study cited by the guidelines, adult cats preferred a 34 x 15 inch (86 x 39 cm) box over a smaller one. AAHA says the same 1.5× rule means "most manufactured boxes are not large enough."
Budget alternatives the guidelines name
- Concrete mixing trays
- Sweater boxes
- Under-bed storage containers (the lid can stand upright behind the box to protect the wall)
Special cases
- Kittens, seniors and cats with mobility problems need low sides (Cornell, OSU).
- Cats that stand while urinating may do better with a high-sided box (AAFP/ISFM).