Litter looks cheap until you do the yearly math
A bag of litter is a $20 impulse buy — until you realize you buy one every month for fifteen years. This comparison prices the four main litter types (clumping clay, crystal, natural paper, and natural wood) for your exact number of cats, so the "cheap" bag and the "expensive" bag compete on the only number that matters: dollars per month.
The formula
Monthly cost = cats × (lbs used per cat per month ÷ bag size in lbs) × bag price. The defaults: clumping clay $22 for a 40-lb bag at 10 lb per cat per month; crystal $30 for an 8-lb bag (roughly one bag per cat per month); natural paper $25 for 24 lb at 12 lb per cat per month; natural wood pellets $18 for 40 lb at 12 lb per cat per month. Cost per cat per month is simply the monthly total divided by your cats. The boxes stepper splits the total into a per-box figure for planning refills — it does not change the total, because total cost is driven by cats and usage rate, not box count.
Why usage rate is the whole game
The single biggest lever is not the litter type — it is how much you waste. A diligent daily scooper stretches a bag dramatically; a skipped week means dumping and refilling. That is why the usage slider is front and center: move it from 8 to 16 lb per cat per month and watch the "cheap" clay double in price. The comparison only means something with your honest number, so set it to what you actually observe, not what the bag promises.
Beyond price: what the table does not show
Dollars per month is not the whole decision, and an honest comparison says so. Crystal loses on price but wins on dust and on change frequency — allergy-sensitive households often pay the premium gladly. Wood pellets win on price but some cats dislike the texture underfoot, and a cat that avoids the box is the most expensive problem on this page. Paper appeals to environmentally minded owners and tracks less than clay, at a moderate premium. Clay remains the default for a reason: cats accept it readily, it clumps reliably, and it is available everywhere. The practical move: pick the cheapest type your cat actually uses happily. Run the table with your cat count, note the yearly spread, and then let the cat vote — because the "winner" your cat rejects is the most expensive litter of all.
Reading the winner honestly
Wood pellets usually win on raw dollars; crystal usually loses but buys near-zero dust and less frequent changes — time has value too. Paper sits in the middle and appeals to eco-minded owners. The "yearly savings vs. priciest" row quantifies the spread: in multi-cat homes it routinely exceeds $200 a year, which is real money for identical function. Pair this with the Cat Cost Calculator to see litter's share of your whole cat budget.
