Short answer
How often should you change cat litter?
Scoop clumps and stool at least once a day — twice a day in a multi-cat home. How often you replace all of it depends on the litter: about every 1–4 weeks for clumping litter, and about once a week for non-clumping litter. Wash the box with hot water and a mild detergent when you do.
Typical intervalScoop daily · full change every 1–4 weeks
Scoop every day
Scoop the box at least once a day: remove urine clumps and stool, then top up with a little fresh litter. Two board-certified veterinary behaviorists writing for VCA Animal Hospitals recommend cleaning boxes daily, removing stool and wet areas of urine. The UK charity Cats Protection suggests scooping clumping litter at least twice a day, which is a good target for multi-cat homes.
Daily scooping doubles as a quick health check. If the number or size of urine clumps, or the look of the stool, suddenly changes, note it and ask your vet — changes in litter box habits can be linked to health. If your cat is getting subcutaneous fluids at home, these notes are worth keeping alongside that record for your next visit.
How often to do a full change
Topping up never really makes the box fresh. How often to dump everything, wash the box and refill depends mostly on whether the litter clumps:
| Litter type | Every day | Full change |
|---|---|---|
| Clumping (clay, tofu and other clumping litters) | Scoop clumps and stool, top up | About every 1–4 weeks |
| Non-clumping (urine soaks into the litter) | Remove stool | About once a week |
- Clumping litter: VCA notes the whole box may only need changing every 2–4 weeks; Cats Protection recommends replacing it weekly. The range is wide because the number of cats, box size and litter quality all vary. With one cat and a big box, start at every 2–3 weeks; with several cats, or if you can smell it, make it weekly.
- Non-clumping litter: urine is absorbed and can’t be scooped out, so plan on a full change about every week.
Brands differ a lot, so the bag’s own guidance is worth a look too. Whatever you use, if you can smell the box, it’s time for a full change — Cats Protection points out that an odor means it’s time to rethink the litter or the cleaning routine.
How to wash the box
Wash the box every time you do a full change:
- Empty all the old litter (check the bag and your local rules before flushing any litter).
- Wash with hot water and a mild detergent, then rinse well.
- Let it dry completely, then refill to about 3–4 cm.
What to avoid:
- Phenol-based disinfectants: they are toxic to cats.
- Strong-smelling cleaners and scented deodorizers: leftover smells can make a cat avoid the box and go somewhere else.
Common mistakes
- Topping up instead of changing: the box gets fuller while the bottom layer stays months old.
- Too few boxes: the usual rule is one per cat plus one, in different places. Two cats sharing one box often means one of them stops using it.
- The wrong spot: next to food and water, in a busy hallway or by the front door, where the cat gets interrupted.
- Masking odor with deodorizer: the smell is your cue to clean, not something to cover up.
- Changing everything at once: cats can be picky about their toilet. Switch litter types one box at a time.
How to remember
Tie daily scooping to something you already do, like after dinner or before bed, and it becomes automatic. What actually gets forgotten is the full change and wash every few weeks: which weekend was it? When two people share the care, it’s easy for each to think the other one did it.
Tracking “full change + wash” as a recurring item beats relying on memory. Add the other regular care too — nail trims and deworming — so you can see which one is coming up next. Washing the bedding fits the same rhythm, especially if your cat sleeps on the bed (see how often to wash sheets).
Keep track of it with Againday
Scooping becomes a habit. The full change and box wash every few weeks is the part that slips — and in a shared home, everyone assumes someone else did it.
- Add a new item called “Change litter + wash box” and set How Often to “Every 2 weeks”.
- Give it the tag “Pets” so you can filter it with related items.
- Set its reminder time to 10:00 AM. You’ll get one notification on the day it’s due.
- Put it in a shared list such as “Home”. Whoever does it marks it done, and everyone sees who did it.
- When it’s done, tap the cycle ring to mark it done. Forgot to log it? Add a past date from the item’s page.
- Add a note to each entry, for example: “Switched to tofu litter, filled to 5 cm”.
Againday is free for 3 items, with shared lists, widgets and reminders included. Againday Pro is one purchase, not a subscription.
Frequently asked questions
- Do I really need to replace all the litter? Can’t I just top it up?
- Yes, you need full changes. Scooping and topping up removes what you can see, but urine and bacteria still build up in the remaining litter and on the bottom of the box. Clumping litter needs a periodic full change and wash; non-clumping litter needs one about every week.
- How many litter boxes does a cat need?
- The common rule is one box per cat plus one extra, in different locations — three boxes for two cats. It isn’t based on hard evidence, but it’s widely recommended; in a multi-cat home you can adjust it to how your cats actually get along.
- How deep should the litter be?
- One common recommendation is 3–4 cm (about 1.5 inches). Very deep litter makes an uneven surface that some cats dislike. A cat with a condition that increases urine output needs enough depth to soak it up, and if your cat clearly prefers a different depth, go with that.
- Can I use bleach or disinfectant on the litter box?
- For routine cleaning, hot water and a mild detergent are enough. Avoid phenol-based disinfectants, which are toxic to cats, and strongly scented cleaners or deodorizers that can put a cat off the box. If your vet recommends a specific disinfectant, follow that advice.
Sources
Intervals vary by product, model and situation. When the manual or a professional says otherwise, follow them.
- Cat Behavior Problems – House Soiling — VCA Animal Hospitals (Debra Horwitz, DVM, DACVB; Gary Landsberg, DVM, DACVB)
- “To pee, or not to pee…” – litter tray advice — Cats Protection (The Cat, Autumn 2013; by Vicky Halls, registered veterinary nurse)