Trash Bag Sizes: The Complete Chart for Gallons, Liters, and Dimensions

Most trash bag problems start with a bag that is almost the right size. A 13-gallon liner stretched over a wide kitchen rim splits at the seam. A 55-gallon bag dropped into a 40-gallon can wastes film and money. The capacity on the box does not tell you whether the bag fits. Trash bag sizes are three numbers, not one: volume, flat width, and length.

This guide gives you the numbers the industry uses, starting with the standard range from 4 to 95 gallons. You will see what each gallon size means in inches and centimeters, how to measure a can in three steps, how UK litre sizing maps to US gallons, and how film thickness changes performance. Use the chart to choose a size, and the measuring steps when the chart is close but not exact.

The Short Answer

• A standard kitchen bag is 13 gallons, about 24 inches wide and 27 inches long.
• The most common trash bag sizes are 4, 13, 33, and 55 gallons.
• UK bin liners are sold by volume: 30L, 50L, 80L, 120L, and 240L.
• Two formulas cover most cases: flat width = can perimeter ÷ 2, and bag length = can height + 3 to 4 inches.

How Are Trash Bag Sizes Measured?

Trash bag sizes come in three forms: volume in gallons or liters, flat width, and length. Volume tells you capacity, not fit.

Gallons vs. liters

For example, a 13-gallon bag holds about 49 liters of waste, but two 13-gallon cans can have very different shapes: one tall and narrow for a cabinet gap, one short and wide for an open kitchen. Volume alone will not tell you which bag stays on the rim.

The US gallon is 3.785 liters. The UK gallon is 4.546 liters, which is why a British “gallon” bag is larger than an American one. Most of the world sells liners in liters, so a conversion is useful even if you buy in gallons.

Dimensions: width × length

A trash bag is a tube sealed at one end. The “flat width” is half the tube’s circumference, so it must be at least half the perimeter of the can’s opening. The length has to cover the inside of the can plus enough film to fold over the rim.

So a bag can be the right volume and still the wrong size. If the flat width is too small, the bag tears at the seam when you pull it over the rim. If the length is too short, it slips inside the can as soon as you add weight.

The gallon number is a nominal capacity, not a fit guarantee: a 13-gallon bag has enough film to line a 13-gallon can and still fold over the rim.

How Do You Measure a Trash Can?

Measure the rim, then the height, then add the overhang. A tape measure and two minutes are enough.

Step 1: measure the perimeter

For a square or rectangular can, measure the rim at the top, across the outside edge. Add the length and width, and that sum is the minimum flat width. The math is perimeter divided by two, which works out to length plus width.

For a round can, measure the diameter across the opening and multiply by 3.14. Divide by two for the flat width. Add an inch or two for slack; a bag that is slightly loose is easier to handle than one that is tight.

Step 2: measure the height

Next, measure from the inside bottom of the can to the top rim. A recessed base or an outside lip adds an inch you do not need, and the bag will bunch at the bottom. Write the number down in inches, because bag lengths come in inches.

Step 3: add the overhang

Finally, add 3 to 4 inches to the height so the bag can fold over the rim and stay put. A 24-inch can needs a bag at least 27 inches long. For a can with a wide lip or a locking lid, add 4 to 5 inches instead.

Trash Bag Size Chart: What Size Do You Need?

Most homes need 13 gallons at 24 × 27 inches. The chart below covers 4 to 95 gallons.

Full size chart

Sizes below are the North American retail standards, in inches and centimeters. All dimensions are flat width × length. Figures are typical liner sizes; exact sizes vary by brand and product line, so check the pack label before a bulk order.

Capacity	Liters	Flat width × length (in)	Flat width × length (cm)	Typical use
4 gal	15	17 × 18	43 × 46	Bathroom, office, bedroom bins
8 gal	30	22 × 24	56 × 61	Small kitchen, laundry, general waste
10 gal	38	24 × 24	61 × 61	Kitchen, medium waste
13 gal	49	24 × 27	61 × 69	Standard kitchen step can
13 gal tall	49	24 × 30	61 × 76	Tall, narrow kitchen cans
20 gal	76	28 × 34	71 × 86	Breakrooms, large kitchens
30 gal	114	30 × 36	76 × 91	Commercial bins, events
33 gal	125	33 × 39	84 × 99	Wheelie bins, yard waste
39 gal	148	33 × 41	84 × 104	Lawn and leaf, outdoor cleanup
45 gal	170	40 × 46	102 × 117	Large commercial bins
55 gal	208	38 × 58	97 × 147	55-gallon drums
60 gal	227	38 × 60	97 × 152	Drum liners, bulk waste
95 gal	360	50 × 70	127 × 178	96-gallon carts

The 13-gallon row is the one most households need, and it has its own guide covering tall versus standard cans: 13-gallon tall kitchen bags.

Can size to bag size

The table maps common cans to trash bag sizes and dimensions.

Can	Typical capacity	Bag to use
Desk or office bin	10–12 in high	4 gal, 17 × 18 in
Kitchen step can	13 gal	13 gal, 24 × 27 in
Wheelie bin	32 gal	33 gal, 33 × 39 in
Steel drum	55 gal	55 gal, 38 × 58 in
Cart	96 gal	95 gal, 50 × 70 in

When a can sits between two trash bag sizes, go up. A slightly large bag folds over the rim and stays; a slightly small one tears or disappears into the can.

How to read a bag label

A bag label carries five numbers, and only one of them is the capacity. The dimensions are the flat width and the length, not the opening; a 24 × 27 bag opens to a circle about 15 inches across.

The gauge is the film thickness, in mils for LDPE and microns for HDPE. Also, the count tells you how many bags are on the roll or in the box, which matters more than the price when you compare brands. The load rating, when the pack shows one, tells you how much weight the bag can carry.

For compostable bags, the label should also carry a certification mark such as BPI, OK Compost, or OK Compost HOME. A bag that says “biodegradable” without a mark has no verified timeline or residue limit.

Common sizing mistakes

Measuring the can body instead of the rim is the most common error. Many cans taper toward the base, so the body is narrower than the rim; a bag sized to the body will not stretch over the top. Measure the widest point, which is the rim.

Buying by volume alone is the second. Two 13-gallon cans can need different bags if one has a wide rim and the other a narrow one. Check the flat width against the perimeter, not just the gallon number.

Sizing down to save film is the third. A bag that is too small tears at the seam, and as a result the roll gets used faster because each bag fails sooner. The fourth is forgetting the overhang: a bag that matches the can height exactly will slide in as soon as it is loaded.

What Do UK Buyers Call Trash Bags?

Bin bag, dustbin bag, rubbish bag, and bin liner all mean trash bag. The sizing system is different too. UK trash bag sizes are sold by volume in liters, not gallons, and the common sizes are 30L, 50L, 80L, 120L, and 240L.

Rough conversions: 30L is about 8 gallons, 50L about 13 gallons, 80L about 21 gallons, 120L about 32 gallons, and 240L about 63 gallons. The numbers are close enough for household use, but check the rim width on 240L wheelie-bin liners, because bin shapes vary between councils.

However, a UK gallon is 4.546 liters, not 3.785. If a listing says “gallon” without a country, assume the US measure unless the seller is British.

How Thick Should a Trash Bag Be?

For a kitchen can, 0.9 mil LDPE is the everyday standard. Sharp waste needs 1.5 mil; contractor debris needs 3.0 mil.

Thickness decides whether a bag survives a broken plate or a handful of grass clippings. Two units are in use: mil, equal to one thousandth of an inch, and micron, equal to one thousandth of a millimeter. One mil is 25.4 microns.

High-density polyethylene, or HDPE, is measured in microns. For instance, its molecules pack tightly, so a 6 to 15 micron film is strong enough for light waste. Low-density polyethylene, or LDPE, is measured in mils. It stretches around sharp edges instead of splitting, which is why heavy-duty bags use it.

Film	Thickness	Typical use
HDPE liner	6–10 µ	Office, bathroom, light waste
HDPE liner	11–15 µ	General household waste
LDPE	0.9 mil (23 µ)	Standard kitchen bag
LDPE	1.5 mil (38 µ)	Heavy waste, sharp edges
LDPE	3.0 mil (76 µ)	Contractor, construction debris

Thickness is not the only variable. Resin blend, seal quality, and bag construction change performance at the same gauge. For a deeper comparison of gauge, load ratings, and puncture resistance, see trash bag thickness.

Compostable Bags and Certifications

“Biodegradable” and “compostable” are not interchangeable. Biodegradable means a material will break down eventually, with no promise about how long or what is left behind. Compostable means the material meets a specific standard for disintegration, biodegradation, and ecotoxicity in a defined time. Compostable trash bag sizes follow the same gallon scale, though the film is usually thicker.

Four standards matter. In the United States, ASTM D6400 covers industrially compostable plastics, and BPI certifies products against it. In Europe, EN 13432 is the equivalent standard, and TÜV Austria’s OK Compost and OK Compost HOME marks certify industrial and home composting respectively.

Biopakbag’s compostable bag range carries BPI and OK Compost certification; the mark printed on each pack identifies the standard that applies to that product.

That said, the composting environment matters as much as the label. The EPA’s guidance on composting at home notes that backyard piles rarely reach the temperatures needed for compostable bags and foodservice ware, and recommends commercial facilities for those materials. A bag certified for industrial composting is not automatically suitable for a home pile.

Strength is the other common question. Certified compostable liners are strong enough for food scraps and daily kitchen waste, but they stretch less than LDPE. The resin blend, usually PLA or PBAT with starch, does the work. For a side-by-side comparison of the certifications and what each one tests, see the compostable bag certification guide.

Frequently Asked Questions (FAQs)