Start with the can’s capacity in gallons, then check the bag’s flat size. Glad says to measure the bin’s height, width and depth, “then choose a bag that’s slightly larger in capacity to ensure a snug fit without tearing.” Glad lists the common sizes as 4 gallons for the bathroom, 8 for the office, 13 for the kitchen and 30 or more for the garage or outdoors.

Glad’s size chart (flat bag size, width x length)

Glad size class Capacity Example bag size (inches) Glad says it’s for
Small 2.6 to 4 gal 13 1/4 x 16 1/2 to 17 x 18 Bathroom, travel
Medium 8 gal 21 5/8 x 23 Laundry, office, compact kitchen
Kitchen / Tall 13 to 20 gal 23 15/32 x 25 3/8 to 23 21/32 x 30 13/16 Kitchen
Large 30 to 33 gal 30 x 33 to 33 1/2 x 36 Outdoor, garage
X-Large 39 gal 32 1/2 x 41 Industrial, cleanup

Glad prints these in feet and inches; they are shown here in inches. For one specific bag, Glad lists its ForceFlex MaxStrength 13-gallon kitchen bag at 23 3/4 x 25 3/8 inches (60.3 x 64.5 cm) and says it fits “containers up to 2 ft.”

Hefty’s lineup uses similar capacity steps: 4-gallon small bags, 8-gallon medium bags, 13-gallon kitchen bags, 30-, 33- and 39-gallon large bags, and 39-gallon lawn and leaf bags.

Pitt Plastics’ fit chart for common cans

Pitt Plastics, a can liner maker, publishes a fit chart by receptacle type, mostly commercial cans, in its Pitt-Fit brochure. Its liners run longer than Glad’s bags at similar capacities, and its sizing rule (below) builds in overhang.

Can Pitt liner size (inches)
Wastebasket, 7 to 10 gal 22 x 25
Wastebasket, 12 to 16 gal 24 x 32 (low density) or 24 x 33 (high density)
Round container, 22 gal; Slim Jim, 23 gal 29 x 44
Round receptacle, 32 gal 33 x 44
Round receptacle, 44 gal 37 x 50
Round receptacle, 55 gal 41 x 54

Compare a 32-gallon round receptacle at 33 x 44 inches in Pitt’s chart with Glad’s 30- to 33-gallon class at up to 33 1/2 x 36. If your outdoor can is tall, length is the dimension to check.

How to measure an odd-size can

Two liner makers publish the same width rule and slightly different length rules:

Maker Bag width Bag length
Pitt Plastics Half the can’s outer circumference Height + half the bottom diameter + 3 in
International Plastics Circumference divided by 2 Height + half the diameter + 4 in

For square or rectangular cans, Pitt says to “use the diagonal of the receptacle bottom rather than the diameter.” If you plan to tie the bag closed, International Plastics says to add the full diameter plus 4 inches to the can’s height instead.

Branded cans with coded liners

Some can makers size their own liners. simplehuman sells “custom fit liners” by code letter, for example Code H for 30 to 35 liter cans and Code K for 35 to 45 liter cans, and says they are “designed to fit each of our cans perfectly.” If you own one of these cans, buying by its code is simpler than matching gallons.

Check these bags on Amazon

FAQ

What size trash bag fits a standard kitchen can?

Glad says most kitchen trash bags are 13 gallons, which fits standard under-sink or freestanding kitchen bins, and that larger bins may need 20 gallons.

How do I find the bag size for an odd-size can?

Pitt Plastics says to use half the can’s outer circumference for bag width, and the can’s height plus half the bottom diameter plus 3 inches for length. International Plastics uses the same width rule but adds 4 inches for overhang.

Will a 13-gallon bag fit a 10-gallon can?

Glad advises choosing a bag slightly larger in capacity than the bin for a snug fit without tearing, so a modestly larger bag is the maker’s suggested direction. Check the flat bag size against your can.

Sources