How often should you change cat litter? Scoop clumps and solids daily, then do a full change on a schedule set by your litter type: clumping litters every 2–4 weeks, non-clumping litters at least weekly, and roughly twice as often in multi-cat homes. Those are the headline numbers — the details below turn them into a schedule for your exact litter.
These intervals are general guidance, not rules from your cat. Some boxes need refreshing sooner; a few stretch longer. This guide gives you the litter-by-litter schedule, the warning signs that say "change it now," and the routine that makes full changes fast.
The Litter-by-Litter Schedule
Full-change frequency depends mostly on whether a litter clumps — because scooping a clumping litter removes the soiled material daily, while non-clumping litter accumulates urine until you replace it.
The Humane Society of the United States suggests changing clumping litter every two to three weeks with daily scooping, and non-clumping clay about twice a week. Manufacturer guidance for specific litters can stretch or shorten that, but the clumping/non-clumping split holds across materials.
| Litter type | Scoop | Full change (1 cat) | Notes |
|---|---|---|---|
| Clumping clay | Daily | Every 2–4 weeks | Top up after scooping to keep 5–8 cm depth |
| Non-clumping clay | Solids daily | About twice a week | Urine stays in the box between changes |
| Silica crystal | Solids daily, stir crystals | Every 3–4 weeks per manufacturer | Change sooner if crystals are saturated or yellowed |
| Recycled paper | Solids daily | 1–2 times a week | No clumps; odour builds quickly |
| Wood pellets | Solids daily, sift sawdust | Weekly | Pellet systems need a sifting routine |
| Tofu (plant-based clumping) | Daily | Every 2–4 weeks | Fast clumping keeps the rest of the box clean |
| Cassava (plant-based clumping) | Daily | Every 2–4 weeks | Larger granules, tight clumps; same rhythm as tofu |
Multi-cat homes: treat these intervals as ceilings and expect to change about twice as often per box — or better, add boxes so each one carries less load.
Read the Signals, Not Just the Calendar
Days-on-a-calendar is a starting point. Your box will tell you when it's actually time, and the signals are more reliable than any fixed number.
Smell that survives scooping
If the box still smells within a day of a thorough scoop, odour has soaked into the base litter. No amount of topping up fixes that — it's full-change time. (Warm weather accelerates this; here's why litter smells worse in summer.)
Clumps that fall apart
Clumping litter loses performance as the un-soiled portion absorbs ambient moisture. When clumps start crumbling on the scoop instead of lifting out whole, the remaining litter is close to spent.
Sediment at the bottom
A layer of fine, packed residue on the floor of the box means broken-down litter is accumulating. That layer holds odour and clings to paws — time to empty, wash, and refill.
Your cat hesitates
Perching on the edge, digging endlessly without settling, or eliminating right beside the box are classic "too dirty for me" complaints. Cats often enforce a stricter standard than their humans.
Adjusting for Your Household
Multiple cats: more traffic per box means faster saturation. Double the change frequency, or run one box per cat plus one spare.
Kittens: small bladders, frequent visits, and a habit of tasting things. Keep boxes extra clean and shallow, and expect more frequent full changes.
Senior cats: older cats can be less tolerant of a dirty box and may have conditions (like kidney disease) that increase urine volume. If urine output visibly rises, tighten the schedule — and mention it to your vet.
Covered boxes: hoods trap humidity and odour, so covered boxes typically need changes toward the early end of every range.
Seasons: heat and humidity speed up odour chemistry, so summer usually pulls the schedule earlier, while a dry Canadian winter is more forgiving — but closed windows mean you notice everything more. Let the signals above, not the calendar, make the final call in both seasons.
The Full-Change Routine (10 Minutes, Done Well)
1. Empty the box completely — old litter, sediment and all.
2. Wash with warm water and a mild, unscented dish soap. Skip strong-smelling cleaners: residual odours can put cats off the box, and ammonia-based products read as "another cat was here." Never mix cleaning chemicals.
3. Dry thoroughly. Moisture left in the corners is a head start for the next odour cycle.
4. Refill to 5–8 cm. Too shallow and urine hits plastic; too deep and clumps break on removal.
5. Reset your top-up rhythm: after daily scooping, add a little fresh litter to hold the depth steady between full changes.
What a Realistic Schedule Costs
Once you know your change frequency, monthly consumption is simple math: depth × box footprint × changes per month, plus top-ups. For a single-cat home on a clumping litter with a 3-week cycle, most people land in the range of one to two 2.4 kg bags a month — our Canadian cost-per-month breakdown runs the numbers by litter type.
Consistency is where bulk buying earns its keep: if your schedule consumes a bag every couple of weeks, a bulk 6-pack bundle or a Subscribe & Save delivery matched to your cycle costs less per bag and removes the "we're out of litter" emergency run entirely.
The reverse also holds: if you're still experimenting with litters or your cat is mid-transition, buy small until the schedule stabilizes. Bulk savings only pay off once you know your monthly burn rate.
Disposing of the Old Litter
Where the old litter goes depends on the material. Clay and silica go in the garbage, bagged. Plant-based litters have more routes, with one important split:
Tofu litter can be flushed in small amounts at a time — never the whole box at once — and only if your municipality permits it and you're not on a septic system. When in doubt, bag it for the garbage or compost it away from food gardens.
Cassava litter is not flushable. Dispose of it in the garbage or compost — never down the toilet. The full breakdown of what can and can't be flushed is in our honest guide to flushable cat litter.
FAQ: Changing Cat Litter
How often should tofu cat litter be fully changed?
With daily scooping, every 2–4 weeks for one cat — sooner if smell persists after scooping or clumps start crumbling. Multi-cat homes should roughly double the frequency per box.
Can I just keep scooping and topping up without full changes?
Not indefinitely. Even with perfect scooping, fine soiled particles and absorbed moisture accumulate in the base litter. Skipping full changes is the most common cause of a box that "always smells" despite daily scooping.
What do I do with the old litter when I change it?
Bag clay or silica for the garbage. Tofu litter may be flushed in small amounts where your municipality allows it (never on septic); cassava litter should never be flushed — garbage or compost only.
Does adding baking soda let me change litter less often?
It can soften odour between changes, but it doesn't remove soiled material — so it delays the symptom, not the cause. Treat additives as a supplement to the schedule, not a replacement.
How full should the litter box be?
Aim for 5–8 cm of litter. Shallower lets urine pool on plastic; deeper wastes litter and weakens clump removal.
