Litter box sizing (1.5× rule)

The rule spelled out

• Length ≥ 1.5× cat's body length. Most adult cats need boxes 22"+ long. Storage bins often work better than commercial 'jumbo' boxes.
• N cats + 1 box, in ≥ 2 different rooms. A row of boxes side by side counts as one location to the cat.
• Unscented, clumping clay preferred by most cats in preference studies.
• Depth 2–3 inches of litter — deeper does not equal more attractive.
• Scoop daily. Wash and refill weekly.

Senior cats and kittens

Arthritic seniors need low-entry boxes (≤ 2" lip on one side). Kittens under 12 weeks need shallow trays or ramps. Both groups are frequently blamed for 'inappropriate elimination' when the real problem is a box they physically can't use comfortably.

Why it matters

The most common reason cats stop using the litter box is that the box is too small, too covered, too dirty, or there aren't enough of them. Fixing the setup solves more house-soiling cases than any medication ever prescribed for it.