How to use the cat litter cost calculator
- Enter the price per bag and the bag size in pounds.
- Enter the number of litter boxes, the litter per full change for one box, the full changes per week and any top-up per week.
- Read the headline for the cost per month and the table of weekly, monthly and yearly costs.
- To compare, open More options and enter another litter's price and bag size. The difference per year is shown, with a cheaper litter in parentheses.
Formula
litter per week = boxes x (litter per change x changes per week + top-up per week)
cost per pound = price / bag size
cost per week = cost per pound x litter per week
cost per year = cost per week x 52; per month = cost per year / 12
Weekly and yearly costs are rounded to the cent, half up. Monthly cost is the yearly cost divided by 12, so it averages months with four and five weeks.
$18 for a 20 lb bag, 5 lb a week
$18 / 20 lb = $0.90 per pound. At 5 lb a week that is $4.50 a week, $234.00 a year and $19.50 a month. The year uses 5 x 52 = 260 lb, which is 13 bags.
For two boxes, each changed every other week with 4 lb, plus 1 lb a week of top-up each, the litter is 2 x (4 x 0.5 + 1) = 6 lb a week, which costs $280.80 a year, or $23.40 a month. Another litter at $27.50 for 25 lb costs $1.10 per pound, so 5 lb a week is $286.00 a year, $52 more.
What drives the cost
The price per pound matters, but so does how much you use. A pricier litter that clumps tightly and needs less can cost the same as a cheap one that you replace more often. Measure your own use for a couple of weeks and enter that, instead of guessing.
The comparison field is for exactly that case. Enter the weekly use you expect with the first litter, then another bag price and size, and you see what the same use would cost. If the second litter would be used at a different rate, run the page again with that rate.
Fitting it into the pet budget
Litter is one line among food, vet care and supplies. The Annual Pet Cost Calculator adds them up over a year and a lifetime, the Unit Price Calculator compares bag sizes, and the Pet Insurance Break-Even Calculator covers the cost of care.
Assumptions and limits
- Use stays the same every week of the year. Seasonal changes and extra cats are not modeled.
- Prices are the ones you enter. Sales, shipping and delivery fees are ignored.
- The comparison litter is used at the same weight per week as the first.
- Weekly use must be above zero, and half a pair of comparison fields is refused.
Frequently asked questions
How much does cat litter cost per month?
Divide the bag price by the bag weight to get the price per pound, multiply by the pounds you use in a week, then by 52 and divide by 12. $18 for 20 pounds at 5 pounds a week is $19.50 a month.
How much litter do I need per week?
It depends on the number of boxes, how often you change them and how deep you fill. Enter the weight per full change and the changes per week, plus any top-up. The page multiplies it out across your boxes.
How many bags of litter will I use in a year?
Divide the pounds used in a year by the bag size. Five pounds a week is 260 pounds a year, which is 13 bags of 20 pounds. The page shows the decimal and the number of bags to buy, rounded up.
Is a cheaper litter always cheaper to use?
Not necessarily. The cost per pound is only half of it, since the litter you need per week can differ between products. Compare the cost for the weight you actually use of each, not just the price tags.