Litter & Litter Tech
Best Cat Litter Box Liners (2026)
A liner that fits is a two-minute box strip. A liner that tears is worse than no liner at all.
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Everyone in this category says they tested twenty litter boxes. We have not tested any, and we say so. What we do instead: compile the published specs, read the manuals, and do the arithmetic on what this gear costs to run and how it behaves once there is more than one cat using it. Every spec is linked to the document it came from. Prices are checked daily — last verified September 25, 2026. Here is exactly how we pick.
Quick picks
Ranked on the published specs and the arithmetic below. Tap any row to jump to the full write-up. We have not tested these — here is exactly how we pick.
| # | Product | Best for | Score | Price |
|---|---|---|---|---|
| 1 | Alfapet Drawstring Cat Litter Box Liners, Extra Large Publishes both a size and a gauge -- 36 by 18 inches at 2 mil -- which is two more numbers than most liner boxes carry. | Stripping a box without lifting it | 7.1 | |
| 2 |  Modkat XL Litter Box Configurable top or front entry from the same shell, with a reusable liner rated for three months instead of a disposable one. | Small flats, and cats that disagree about entry | 7.2 | |
| 3 |  Petmate Jumbo Litter Pan The plain plastic pan that lets you follow the one-box-per-cat-plus-one rule without spending like it. | Extra boxes, cheaply | 7.4 |
#ad Buy links are affiliate links. Prices come from a live daily check; where we have no verified price we say "check price" rather than print a stale one.
Liners are bought on price and abandoned on fit. There is a formula that predicts whether one will work in your box, and almost nobody applies it before ordering.
The sizing formula
A liner does not lie flat in the bottom of a box. It has to reach up and over both end walls to be gathered and tied, so the length you need is:
box length + (2 x wall depth) + about 4 inches to gather
A 20 inch box with 6 inch walls: 20 + 12 + 4 = 36 inches. Alfapet's extra large publishes 36 by 18, so it just fits.
A 30 inch box with 8 inch walls: 30 + 16 + 4 = 50 inches. No liner in this size class fits it, which is why people with large boxes conclude that liners do not work.
Gauge is the second number
Alfapet publishes 2 mil on its extra large, which is the heavy-duty grade in this category. That figure matters because of the specific way liners fail: a digging cat opens a hole, urine passes through it and collects between the liner and the plastic, and now you have a hidden reservoir that is worse than an unlined box.
| Approach | Published spec | Waste | Fits |
|---|---|---|---|
| Alfapet drawstring, XL | 36" x 18", 2 mil, flat bottom | One bag per change | Boxes up to about 20 in with 6 in walls |
| Modkat reusable liner | Published per model | Reusable, washed | Only the Modkat box it is made for |
| No liner | - | None | Any box |
The third row is a genuine option. A box washed properly at every full change does not require a liner at all.
The reusable alternative
Modkat's system takes the opposite approach: a reusable liner designed for one specific box, washed rather than binned. Over a year that is one object instead of roughly fifty bags, which is a real difference for anyone weighing the disposable-plastic trade against the convenience.
The cost is lock-in. A reusable liner fits the box it was made for and nothing else, so the liner decision and the box decision become one decision.
When to skip liners entirely
- Your cat digs to the base. A shredded liner is a trap for urine. This is the clearest exclusion.
- You use an automatic box. Rakes and globes are not designed to operate over a loose liner, and manufacturers generally say so.
- Your box is over about 24 inches. The formula above stops having an answer.
- Your cat hesitated after you added one. The Ohio State Indoor Pet Initiative frames litter box access as a resource question, and a liner is not worth a cat's willingness to use the box.
What a liner is actually buying you
Time at the full strip, and nothing else. It does not reduce scooping, does not reduce odor between changes, and does not extend how long litter stays usable — our cleaning schedule is unchanged either way.
If the full strip is not the part of the job you mind, a liner is a recurring cost for a problem you do not have. In a multi-cat house at four boxes stripped every two to three weeks, it is roughly seventy bags a year — and that is the number worth weighing.
The picks in full
Specs are the manufacturer's own, linked to the page they came from. Prices come from a live daily check; where we have no verified price we say so rather than print a stale one.
Alfapet Drawstring Cat Litter Box Liners, Extra Large
Alfapet · Litter box liner · Our score 7.1/10
#ad Price as of September 25, 2026. Prices move; we check daily. How we're funded.
Publishes both a size and a gauge -- 36 by 18 inches at 2 mil -- which is two more numbers than most liner boxes carry.
Published specs
| Size | 36" x 18", extra large |
|---|---|
| Thickness | 2 mil, heavy duty |
| Closure | Drawstring |
| Base | Flat bottom for secure placement |
| Sifting version | Jumbo sifting liner, 37" x 18" |
A 36 by 18 inch liner wraps a box roughly 20 inches long by 15 wide by 6 deep, because the liner has to reach up and over both walls. The rule: your box length plus twice its depth must be under the liner length. A 30 inch box with 8 inch walls needs 46 inches of liner, and this one does not fit it.
What the specs favor
- Publishes a gauge in mils, which liner packaging usually omits
- Drawstring closes the bag rather than needing a second bag
- Flat bottom sits properly rather than ballooning under litter
- A sifting version exists for people who want to reuse the litter
What they don't
- Cats with strong digging habits claw through 2 mil quickly
- A torn liner leaks under the litter, which is worse than no liner
- Disposable plastic, which is a real trade against the site's lighter-substrate pages
Your cat digs to the base of the box. A shredded liner traps urine underneath itself against the plastic, which is exactly the failure a liner was meant to prevent.
How it scores
Scores are our editorial weighting of the published specs above, not a test result. They are deliberately kept out of this page's structured data.
Modkat XL Litter Box
Modkat · Litter box · Our score 7.2/10
#ad Price as of September 25, 2026. Prices move; we check daily. How we're funded.
Configurable top or front entry from the same shell, with a reusable liner rated for three months instead of a disposable one.
Published specs
| External dimensions | 21" L x 16.3" W x 17" H |
|---|---|
| Liner interior | 20" x 16" x 15" H |
| Entry | Top or front, configurable |
| Liner life | Up to three months (Modkat) |
| Litter type | Any |
Source: Modkat -- XL liner specification pages
Modkat rates its reusable liner at up to three months, so four a year. A ScoopFree needs twelve disposable trays in the same period, and the Litter-Robot around 156 drawer liners. Reusable is not a green talking point here, it is the cheapest consumable model of the three.
What the specs favor
- Top or front entry from the same box -- you can change your mind after the cat has
- Reusable liner rated at three months, not a monthly disposable
- Tall 17-inch shell contains scatter and spray
- Smallest floor footprint here at 21 x 16.3 inches
What they don't
- Liner interior is 20 x 16 inches -- less usable floor than the IRIS or the Frisco
- Top entry excludes kittens and senior cats entirely
- Costs several times a plain pan of the same capacity
You have a kitten or an old cat. Configured top-entry it is unusable for them, and configured front-entry you have paid a premium for a normal covered box.
How it scores
Scores are our editorial weighting of the published specs above, not a test result. They are deliberately kept out of this page's structured data.
Petmate Jumbo Litter Pan
Petmate · Litter box · Our score 7.4/10
#ad Price as of September 25, 2026. Prices move; we check daily. How we're funded.
The plain plastic pan that lets you follow the one-box-per-cat-plus-one rule without spending like it.
Published specs
| External dimensions | 22.05" x 16.55" x 6.5" |
|---|---|
| Wall height | 6.5" |
| Type | Open pan, no cover |
| Litter type | Any |
Source: Amazon -- Petmate 22184 Jumbo Litter Pan listing
Cornell's guidance is one box more than you have cats. For three cats that is four boxes. The cheapest automatic box on this page is $269.99 -- four plain jumbo pans is a fraction of one of those, and four boxes beat one clever one every time.
What the specs favor
- Cheap enough to buy four without thinking about it
- 22 inches long, which is genuinely jumbo for a plain pan
- Open, uncovered, low -- the configuration cats prefer
- Nothing to break, nothing proprietary
What they don't
- 6.5-inch walls will not contain a cat that sprays standing up
- No scatter shield at all
- Thin plastic scratches, and scratched plastic holds odor
Odor or scatter is your actual complaint. This pan solves the count problem, not the containment problem -- pair it with a high-sided box rather than replacing one.
How it scores
Scores are our editorial weighting of the published specs above, not a test result. They are deliberately kept out of this page's structured data.
Common questions
Do cat litter box liners work?
What size litter box liner do I need?
Do liners stop cats using the litter box?
How thick should a litter box liner be?
Are reusable liners better than disposable ones?
Sources
Read next
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- Best Cat Litter Disposal Systems (2026)
Three approaches to getting litter waste out of the house, compared on published capacity and recurring cost.
- Best High Sided Litter Boxes (2026)
High-sided boxes compared on published wall height and floor, and how to tell a spraying problem from a digging one.
- Best Litter Box Furniture and Enclosures (2026)
Litter box enclosures compared on published interior dimensions and cat-door size, with the footprint arithmetic.