One cat runs $9-$15 a month on clay (budget to premium), $4-$9 on pine pellets, and $22-$24 on silica subscriptions like PrettyLitter. Two cats on premium clumping clay: about $27.50 a month, $330 a year. The lever that matters isn't brand — it's price per pound times pounds used, and the two move in opposite directions across substrates. Here's the math that holds.
Litter is a commodity sold in deliberately confusing bag sizes, so normalize everything to dollars per pound and pounds used per cat per month. A $22 40-lb bag of premium clumping clay is 55 cents a pound; the same product in 14-lb boxes can top 90. Meanwhile the substrates themselves differ more than any two brands do:
| Substrate | $/lb | Lb/cat/mo | Monthly, one cat |
|---|---|---|---|
| Pine / paper pellets | $0.18 – $0.45 | ~20 | $4 – $9 |
| Non-clumping clay | $0.25 – $0.45 | ~30 | $8 – $14 |
| Clumping clay (budget) | $0.35 – $0.45 | ~25 | $9 – $11 |
| Clumping clay (premium) | $0.50 – $0.60 | ~25 | $13 – $15 |
| Wheat / grass / corn | $0.90 – $1.60 | ~12 | $11 – $19 |
| Tofu | $1.40 – $2.20 | ~8 | $11 – $18 |
| Silica (retail) | $1.75 – $3.00 | ~6 | $11 – $18 |
| Silica (PrettyLitter) | ~$4.00 | ~6 | $22 – $24 |
Notice the pattern: expensive-per-pound substrates use less volume, so monthly costs compress into a $4-$19 band for almost everything except premium silica. That's why "what's the cheapest litter?" is the wrong question and "what's the cheapest monthly cost?" is the right one.
For one cat with daily scooping, a 40-lb bag of clumping clay lasts about 6-7 weeks: you remove clumps, top the box back to 3-4 inches, and dump the remainder monthly, which works out to roughly 25 lb a month. Non-clumping clay needs weekly full changes and consumes closer to 30 lb. Two cats push a 40-lb bag to about three to four weeks. Silica and tofu follow the makers' one-bag-a-month claims per cat — six and eight pounds respectively.
Enter your substrate, the bag you actually buy, and your cat count — the calculator returns monthly, yearly, and autoship-adjusted costs.
Cat Litter Cost Calculator →The discounts are thin: Chewy Autoship takes 5% and ships free, Amazon Subscribe & Save runs 5-15%, and on a $30-a-month clay habit that's $18-$54 a year. The direct-to-consumer brands are a different product: PrettyLitter at $24 a cat ($44 for two) works out to about $4 a pound, and Boxiecat around $1.20 — both are convenience products priced right at the retail math, not below it. A useful sanity check: generic silica math for two cats says 2 × 6 lb × $4 = $48 a month, within 9% of PrettyLitter's own two-cat price. Nobody's getting a bargain; some people are buying crystals that change color with urine pH and a bag that appears at the door.
In the full budget of cat ownership, litter sits between food and vet visits: the cat food calculator prices the daily calories line, and the pet insurance calculator prices the catastrophic one. Together they make the honest number for a decade with a cat.
One cat: $9-$11 on budget clay, $13-$15 on premium clumping clay (about 50-60 cents a pound at 25 pounds a month), $4-$9 on pine pellets, and $22-$24 on silica subscriptions like PrettyLitter. Two cats on premium clay run about $27.50 a month, $330 a year. Multi-cat households generally spend $25-$60 a month on litter.
About 6-7 weeks for clumping clay with daily scooping and a monthly box dump — roughly 25 pounds a month once you account for top-offs. Non-clumping clay changed weekly uses closer to 30 pounds a month, so 5-6 weeks per bag. With two cats, a 40-pound bag lasts about 3-4 weeks.
As a discount, no; as a product, maybe. PrettyLitter works out to about $4 a pound ($24 for a 6-lb bag, one cat) versus 55 cents for premium clay — but silica uses a quarter of the volume, so the monthly gap narrows to roughly $24 versus $13-$15. You are paying for health-monitoring color crystals and doorstep delivery, not savings.