Every litter bag promises weeks of freshness; every cat owner’s nose eventually disagrees. In our cat litter guide we compared the types — this follow-up answers the question we promised to cover in detail: how often to change cat litter, really. Short version: less often than the anxious owners think, more often than the bag suggests. Here’s the honest schedule.
How Often to Change Cat Litter: The Quick Answer
Scoop clumps and solids once or twice a day, every day. Then do a full change — empty the box, wash it, refill with fresh litter — on this schedule:
- Clumping clay: full change every 3–4 weeks
- Silica crystals: full change every 3–4 weeks (stir daily)
- Wood pellets: sift sawdust as it accumulates; full refresh every 2–3 weeks
- Non-clumping clay: full change every 3–5 days
- Paper and plant-based: follow the clumping schedule if it clumps; otherwise treat it like non-clumping
One box, one adult cat, daily scooping — that’s the baseline. Everything below explains when to speed it up.
The Daily Two Minutes That Do 80% of the Work
Full changes get the attention, but daily scooping does the heavy lifting. Removing clumps and solids every day keeps ammonia from building, keeps your cat happy (many refuse a dirty box long before humans smell anything), and stretches the litter itself — a scooped box genuinely lasts those 3–4 weeks; a neglected one turns swampy in ten days.
Two habits make it painless: keep the scoop and a small bin bag right next to the box, and top up a centimetre of fresh litter after scooping to keep the depth around 5–7 cm. Topping up is maintenance, not a substitute for the full change — old litter at the bottom still accumulates odour even if the surface looks clean.
How Often to Change Cat Litter by Type
Clumping clay (every 3–4 weeks). Because urine leaves in the clumps, the remaining litter stays genuinely clean for weeks. Change fully when clumps start crumbling or a background smell survives scooping — those are the two honest signals.
Silica crystals (every 3–4 weeks). Crystals absorb moisture instead of clumping, so give them a daily stir to expose fresh surface. When most crystals have turned yellow or the box smells despite stirring, the fill is saturated — change it.
Wood pellets (full refresh every 2–3 weeks). With a sieve box, wet pellets collapse into sawdust that drops through — remove that layer every day or two and add fresh pellets on top. Even so, do a complete empty-and-wash every 2–3 weeks.
Non-clumping clay (every 3–5 days). There’s no way around it: liquid stays in the litter, so the whole tray must go frequently. This is why the cheapest bag rarely wins the month — a point we counted in the cat litter guide.
The Full Change Routine: Wash, Dry, Refill
A full change takes five minutes done right: empty everything into a bag, wash the box with warm water and mild, unscented soap, dry it completely, and refill to 5–7 cm. Skip bleach and strong-smelling cleaners — feline charity International Cat Care notes that cats can be put off a box by harsh chemical smells, and ammonia-based products actually mimic the odour of urine. While the box is drying, check it for deep scratches: heavily scratched plastic holds odour permanently, and a basic replacement box costs less than a month of premium litter. Used litter always goes in the general waste bin — never the toilet, never the compost (the disposal rules are in the litter guide).
When to Break the Schedule
Speed everything up when circumstances change:
- More cats. One box per cat plus one spare, and full changes roughly a week sooner — smell scales faster than maths suggests.
- Hot weather. In a Lisbon or Algarve summer, odour escalates quickly; scoop twice daily and shorten full-change intervals by about a week.
- Kittens or seniors. More frequent, less predictable use — inspect daily and change on evidence, not on the calendar. If you’re just setting up, our new pet owner checklist covers the starter kit.
- Illness or pregnancy at home. If anyone pregnant lives with you, daily scooping matters medically: the toxoplasmosis parasite needs 24+ hours in the box to become infectious. Ideally someone else scoops; if not, gloves and hand-washing.
- Your cat protests. Going right next to the box is a one-star review of its cleanliness. Believe the cat, not the schedule.
FAQ: Changing Cat Litter
How often to change cat litter for two cats sharing? They shouldn’t share long-term — but with two boxes, scoop both daily and move full changes to every 2–3 weeks for clumping types.
Can I just add fresh litter on top instead of changing it? Topping up between changes: yes, that’s good practice. Topping up instead of ever changing: no — the base layer keeps absorbing odour and bacteria regardless of the clean surface.
Does a covered box change the schedule? It hides smell from you, not from the cat — inside, odour concentrates. Keep the same schedule and consider running a covered box one week shorter.
How much litter should be in the box? Around 5–7 cm. Too shallow and urine hits plastic; too deep and clumps break apart when scooped.
A clean box is the cheapest pet-care upgrade there is. Scoops, mats, sieve boxes and litters for every schedule live in our Pet Shop — and you can sign up on our homepage for 10% off at launch. 🐱