The change interval drives litter cost more than the brand does
What litter costs you depends less on the price of a bag than on how many bags a month you go through. This calculator takes the number of cats, the litter poured per cat at one full change, the change interval, the period you want and the weight of a bag, then reports the changes in that period, the total litter used, the 30-day figure and the bags needed. Change the interval alone and you can see what one extra day between changes saves.
No published usage constant by litter type could be verified. Clay, pine pellets and tofu litter clump differently and the same household gets different results from each, so this page asks for the amount you actually pour instead of a litter type. Only the bag count is rounded up, once at the end, and the formula used is printed with the result. Current as of October 2026.
Box count and placement are outside this page. Do not use this to justify stretching the change interval to save litter: urinary trouble from a cat who holds it in costs far more than litter does. If your cat starts eliminating outside the box after a litter change, or strains with almost no urine passing, call right away. This tool is for reference only and does not replace veterinary care. Contact your veterinarian right away if you notice symptoms or suspect a problem.
Frequently asked questions
No published usage constant by type could be verified. Even one product varies with box size and scooping habits, so entering the amount you actually pour is more accurate.
Add the top-up for one interval into the per-cat amount for a full change. The result then carries that top-up with it.
Bags cannot be split, so the figure is rounded up once at the very end. No intermediate step is rounded up, which keeps the number from inflating.