Alternative Litter cost calculation
Cost per pound
(This was written in 2019 and litter prices have increased since then)
Walnut: US$ .78
Grass: US$ 1.25 (available also for US$ 1.00/lb at Fred Meyers)
Corn: US$ .96
Clay: US$ .47
Calculating the above cost per pound:
Naturally fresh walnut litter: 26lb bag costs US$ 20.50 on Amazon.com and Chewy.com. This works out to $.78/lb.
Worlds best cat litter: 28lb bag costs US$ 27 on Amazon.com and Chewy.com. This works out to $.96/lb.
Frisco Grass Litter: 20lb bag costs US$ 25 on Chewy.com which works out to $1.25/lb.
There are so many brands so we'll average the cost of a few popular brands.
Fresh step clean paws is $18 on Amazon.com for 34.2lbs. It's $12.77 at Walmart for 22.5lbs. This works out to $.54/lb
Tidy Cats 24/7 is $8.78 for 20bs and $14.64 for 35lbs at Walmart, which works out to $.42/lb
Dr. Elseys ultra premium is $18.57 for 40lbs on Amazon.com which works out to $.46/lb
The average cost of these litters is: $.47/lb
Different types of litters weigh different amounts
One big bag of corn weighs much less than one big bag of clay, so they should be compared on volume rather than weight. We'll find the equivalent weight for a set volume of clay, corn, grass, and walnut:
*weights on scale are displayed as lbs + ounces. Walnut for example weighs 5lbs 14.3 ounces = 5.89lbs.
Calculate litter cost per year:
In previous testing, we found a large sized cat (13-15lbs) uses approximately .5lbs of clay litter per day. Clay gets messy, and it's a general recommendation to completely change the litter every 2-3 weeks (15lbs of litter).
Weight of clay litter used per year in standard litter box: 365*.6lbs + (20 litter changes)*15lbs = 482.5lbs * $.47/lb = $226.78
The above is with a traditional litter box and Boxscoop is more litter efficient. In Boxscoop, we find an average sized cat (12-15lbs) uses .45lbs of clay litter per day and usually you can stretch complete litter changes out to between 3 and 4 weeks. Complete litter change would weigh about 9-11 lbs.
Weight of litter used per year in Boxscoop: 365*.45lbs + (15 litter changes)*10lbs per change = 314.25lbs * $.47/lb = $147.70
In 5 days of testing, one 14lb cat used in total .88lbs of litter. It was actually just over 4.6 days in total so on average we used .88lbs/4.6 days = .20lbs per day of Walnut litter. Walnut litter can stay fresh in Boxscoop between 8-10 weeks.
Weight of litter used per year: 365*.20 + (6 litter changes)*4lbs per change = 97lbs *$.78 = $75.66
Corn is 10% lighter than Walnut, and it clumps with similar density. It can stay fresh 5-7 weeks.
Weight of litter used per year: 365*.18 + (8 litter changes)*3.6lbs per change = 94.5lbs * $.96 = $90.72
Grass litter is 25% lighter than walnut and clumps tighter. In Boxscoop you'll use about .14lbs per day. It can stay fresh 10 weeks.
Weight of litter used per year: 365*.15 +(5 litter changes)*3lbs per change = 69.75lbs * $1.25 = $87.19