Price per pound, per cat, per month — subscription math included
| Substrate | $/lb range | Lb / cat / month | Monthly, one cat | Notes |
|---|---|---|---|---|
| Pine / paper pellets | $0.18 – $0.35 | ~20 lb | $4 – $9 | Equine pellets cheapest; sawdust tracking |
| Non-clumping clay | $0.25 – $0.45 | ~30 lb | $9 – $14 | Weekly full changes |
| Clumping clay (budget) | $0.35 – $0.45 | ~25 lb | $9 – $14 | Big-box store brands in 25-40 lb |
| Clumping clay (premium) | $0.50 – $0.60 | ~25 lb | $13 – $17 | Dr. Elsey's tier; ~53¢/lb on Chewy |
| Wheat / grass / corn | $0.90 – $1.60 | ~12 lb | $11 – $19 | Lighter use, biodegradable |
| Tofu | $1.40 – $2.20 | ~8 lb | $11 – $18 | Flushable in small amounts |
| Silica gel (retail) | $1.75 – $3.00 | ~6 lb | $11 – $18 | One 6-lb bag a month per cat |
| Silica subscriptions | $4.00 (PrettyLitter) | ~6 lb | $22 – $24 | $24/mo one cat, $44 two cats |
Per-pound prices from national retailer pricing 2025 (Dr. Elsey's Ultra ~$23/40 lb, PrettyLitter $24/6-lb bag, Boxiecat ~$1.20/lb). Pounds-per-month are planning figures: clumping assumes daily scooping with monthly box dump; silica and tofu follow the makers' one-bag-a-month claims. Two cats don't quite double usage (shared boxes), but linear math is the safe budget.
Litter is a per-pound commodity sold in confusing bag sizes, so the only comparisons that mean anything are dollars per pound and pounds used per month. A $23 40-lb bag of premium clay is 57.5 cents a pound; the same brand in 14-lb boxes can pass 90 cents. Substrates differ more than brands do: the cheapest silica costs triple what the priciest clay does per pound, but you use a quarter as much of it.
Price per pound = bag price ÷ bag size (overrides the $/lb field when you edit it). Monthly cost = cats × pounds per month for your substrate × price per pound. Subscription discount (Chewy Autoship 5%, Amazon Subscribe & Save 5-15%) multiplies the monthly and yearly figures, and the savings line is the discount times twelve. Per cat simply divides by your headcount.
Pick your substrate — the calculator preloads a typical per-pound price and the planning pounds-per-month figure for it. Enter the actual bag you buy and its size, and set your subscription discount to 0 if you buy off the shelf. Two cats? Change the count; the math stays linear, which slightly overstates multi-cat cost and is the conservative budget.
Two cats on premium clumping clay at $0.55 a pound: 2 × 25 lb × $0.55 = $27.50 a month, $330 a year, $13.75 per cat. Adding 5% autoship drops it to $26.13 a month and saves $16.50 a year — convenience money, not life-changing money. Swapping to pine pellets at $0.22 a pound (20 lb per cat) cuts the same household to $8.80 a month, $105.60 a year, a 68% cut.
Now the subscription question done honestly: PrettyLitter at $4 a pound and 6 lb per cat is $48 a month for two cats — within 9% of PrettyLitter's own two-cat price of $44, which tells you the DTC brands price right at the retail math. The health-monitoring crystals and doorstep delivery are what you're buying, not a discount.
For one cat: budget clay runs $9-$14 a month, premium clumping clay (the Dr. Elsey's tier, about 55 cents a pound) about $14-$17, pine and paper pellets $4-$9, and silica subscriptions $22-$48 (PrettyLitter charges $24 for one cat). Add a second cat and clay roughly doubles; most multi-cat households spend $25-$60 a month on litter.
Pine pellets are the floor at 18-35 cents a pound (equine bedding pellets at the hardware store are under 20 cents). Non-clumping clay runs 25-45 cents, clumping clay 35-60 cents, wheat and grass 90 cents-$1.60, tofu $1.40-$2.20, and silica gel $1.75-$4 — the premium silica subscriptions like PrettyLitter work out to about $4 a pound ($24 per 6-lb bag).
For one cat scooping daily, a 40-lb bag of clumping clay lasts about 6-7 weeks, or roughly 25 pounds a month, because you top off what the scoop removes and dump the box monthly. Non-clumping clay full-change weekly uses closer to 30 pounds a month, so the same bag lasts 5-6 weeks. With two cats, expect a 40-lb bag every 3-4 weeks.
The discount is small and the convenience is real. Chewy Autoship takes 5% off and ships free, Amazon Subscribe & Save runs 5-15%, and direct brands like PrettyLitter ($24/month per cat) and Boxiecat (about $1.20 a pound) price convenience into the product itself. On $30 a month of clay litter, autoship saves $18 a year — worth it for the door delivery, not as a bargain.
Planning figures by substrate, per cat, per month: 25 lb of clumping clay, 30 lb of non-clumping clay, 6 lb of silica gel (one bag a month, per the makers), 20 lb of pine or paper pellets, 12 lb of wheat or grass, and 8 lb of tofu. Real usage tracks box size and scooping discipline more than brand.
Sometimes, but the math is about pounds used, not price per pound. Silica and tofu use a quarter of the volume clay does, so $4-a-pound silica can land in the same monthly range as 55-cent clay — that's why PrettyLitter's own two-cat price ($44) sits within a dollar of the generic math ($48). What actually costs more is buying litter in small bags: per-pound prices drop 30-50% from 14-lb boxes to 40-lb bags.