Somewhere between a few pounds and £25 or more per cat, and the frustrating truth is that the bag price barely predicts where you’ll land.

Monthly litter cost is really two numbers multiplied together: what a litre costs, and how many litres your routine burns through. Cheap litter used wastefully outspends premium litter used efficiently with room to spare.

Here’s the honest maths, the typical range for each litter type, and the levers that actually lower the number.

The only formula that matters

Monthly cost = price per litre × litres used per month.

Price per litre is on the shelf edge label (or one division away). Litres per month is the number nobody tracks, and it’s where litter types genuinely separate:

Clumping litters lose only what’s used. You scoop out the clumps, top up what left, and fully reset every few weeks. A cat’s actual consumption drives the cost.

Non-clumping litters lose everything on every change. Because urine spreads invisibly through the bed, the whole tray goes in the bin once or twice a week, clean litter included. The routine drives the cost, and the routine is expensive.

That single difference is why the cheapest bag on the shelf is so often the most expensive litter in the cupboard. Our clumping vs non-clumping guide covers the practical side of the split.

Typical monthly cost by litter type

Illustrative UK shelf prices at the time of writing for one cat with a standard routine; your shelves and your cat will vary, which is exactly what the calculator below is for.

Litter type	Typical bag price	Usage pattern	Typical monthly cost, one cat
Non-clumping clay	Lowest per bag	Full tray change 1 to 2 times weekly	Low bag price, high volume: often £10 to £20
Clumping clay	Low to mid	Scoop daily, reset monthly	Usually £6 to £12
Silica crystals	Mid	Full replacement every few weeks	Usually £8 to £15
Wood pellets	Low	Sift daily, frequent refresh	Usually £6 to £12
Tofu	Mid to high	Scoop daily, reset monthly	Usually £10 to £18
Olive pit	Mid to high	Scoop daily, reset monthly	Usually £12 to £18

Two honest notes on that table. First, ranges overlap heavily because habits matter more than materials: a twice-daily scooper with the right fill depth sits at the bottom of any range, and an over-filler who skips resets sits above the top of it. Second, multi-cat homes don’t just double the number; they slightly better it per cat, because trays and bags are shared infrastructure.

A worked example with real numbers

One 8L bag of OliveScoop costs £20.99 as a one-off at the time of writing, with multipacks cutting the per-litre price. Run it as a clumping litter should be run, scooping daily and removing only what’s used, and that 8L stretches across many weeks for a typical single-cat home, because none of it leaves the tray clean. Whether that lands cheaper or dearer than your current litter depends entirely on what your current routine throws away; a non-clumping tray changed twice a week can bin more clean litter in a fortnight than a clumping tray loses in a month.

Which is the entire point of doing your own maths rather than trusting anyone’s table, ours included.

The five habits that cut the bill

1. Fill to 5 to 7 cm, no more. Overfilling is the most common silent cost; depth beyond what clumping needs just rides along into the bin at reset time.
2. Scoop daily. Left too long, urine migrates and contaminates litter that would otherwise have stayed clean. Daily scooping is odour control and cost control in one motion; the full schedule logic is in <a href=”https://olivescoop.co.uk/blog/how-often-change-cat-litter/”>how often to change cat litter</a>.
3. Give clumps a moment to set before scooping, so they lift whole instead of crumbling and taking clean litter with them.
4. Don’t reset early. With daily scooping, a clumping tray genuinely doesn’t need a full change more than every few weeks; resetting weekly out of habit doubles consumption for no gain.
5. Buy the bigger format once you’re settled. Multipacks and larger bags reliably beat single small bags per litre, and with the right tray count via the n+1 rule, storage does the saving for you.

Work out your household’s real number

The Litter Waste and Cost Calculator. Enter your litter type, bag price, cat count and routine, and it returns your true monthly cost, how much of it is clean litter going in the bin, and what the same routine costs across other litter types. 

Two minutes with real numbers beats any table on the internet.