How often should I change cat litter?
Quick answer
Scoop solid waste at least once a day - twice is better - and completely change clumping litter every two to four weeks for a single cat.
The full answer
If you use non-clumping litter, empty and replace it about once a week.
In a multi-cat home, change litter more often and clean each box daily. Change the whole box sooner if odor lingers after scooping, if clumps crumble or stick to the bottom, if the litter looks damp, or if it has become noticeably dusty. Simply topping up the box with fresh litter does not solve the problem: urine and bacteria stay in the layer underneath. When you do a full change, empty the box, wash it with hot water and a mild unscented soap, dry it completely, and refill with two to three inches (5-7 cm) of litter. Avoid bleach, ammonia-based cleaners, and strongly scented products, since their smell can drive cats away from the box.
Litter box odor is one of the leading reasons cats stop using their box, so consistent cleaning matters far more than buying expensive litter. If a cat is recovering from a urinary problem or is unusually sensitive, some owners do a full change weekly even with clumping litter. Cleaning more often is never harmful to your cat, only a little wasteful.