Between the litter, the liners or cassettes, the carbon filters and — on tray systems — the disposable trays, expect the consumables to overtake the machine’s purchase price somewhere between year one and year three.
Four numbers, multiplied by thirty-six months, added to the machine.
Litter
The largest recurring item on any system. Clumping clay is cheapest per month; tofu costs more and weighs less.
Liners or cassettes
Ordinary bin bags on machines that take them, proprietary cassettes on those that do not. The gap here is larger than it looks — sealed cassettes are the strongest lock-in in this niche.
Carbon filters
Two to four weeks each, a few dollars a pack.
Disposable trays
Only on tray systems, and by far the biggest line when present.
What the arithmetic misses
A refused machine costs everything you spent on it. Acceptance first, running cost second, purchase price third — that is the right order for a decision in this category.
Last reviewed 2026-08-17