Trash can size chart

One US gallon is 3.785 liters and four quarts. Everything in the table below follows from those two conversions, so you can check any row yourself.

Three conversions cover everything in this category, and none of them needs a calculator app.

• Gallons to liters: multiply by 3.785. Thirteen gallons x 3.785 = 49.2 liters.
• Liters to gallons: divide by 3.785. Fifty liters / 3.785 = 13.2 gallons.
• Gallons to quarts: multiply by four. Thirteen gallons = 52 quarts. This is the one you need for cabinet pull-outs, which are almost always quoted in quarts — a 35-quart bucket is 8.75 gallons.

One caution on the metric figures. A US gallon and an imperial gallon are not the same thing: an imperial gallon is 4.546 liters. Every figure on this site is a US gallon, because every product here is sold in the US market. If you are reading a British specification, the same gallon number describes a bigger can.

Size to how often you want to empty the can, not to the size of your household. Odor is a function of time and temperature rather than volume, so a smaller can emptied daily smells noticeably less than a larger one emptied every third day.

If you compost or run a food caddy, drop one row: the wet organic fraction is a small share of the volume but almost all of the smell, so removing it makes a smaller can viable. Compost bins · the full buying guide.

If your can is not in the table — and plenty are not, because manufacturers use non-standard sizes — measure it. Capacity is not the useful number; three dimensions are.

1. Step 01

   Measure the rim circumference

   Run a tape around the outside of the rim, where a bag folds over. This is the number that decides whether a bag stays put, and it is the one nobody thinks to take. A typical 13-gallon can lands somewhere around 40 to 48 inches.

2. Step 02

   Measure the internal height

   From the floor of the can to the underside of the rim. A bag needs this height plus roughly six to eight inches so there is material to fold over the lip.

3. Step 03

   Measure the internal width at the base

   Most cans taper, so the base is narrower than the rim. This is why a bag that fits the rim can still bunch at the bottom, and it is worth knowing before you blame the bag.

With those three numbers you can size a bag properly rather than guessing. The working rule is that a bag's flat width needs to be a little over half the rim circumference to wrap without stretching, and its length needs to be the internal height plus about eight inches. That arithmetic worked through with real bag dimensions.

Outdoor cans follow the same conversions at a bigger scale, but the choice is usually made for you rather than by you. Many American households are on automated collection, where a truck with a mechanical arm grips the cart by its body — and those trucks are built around specific cart profiles, typically 32, 64 and 96 gallons.

So before buying an outdoor can, check what your hauler collects and how. Buying a 96 when your municipality only lifts 64s is an expensive mistake, and buying any cart at all is wasted money if your municipality issues them. Outdoor sizes in detail · our outdoor picks.