Garbage Bag Size Calculator

Bag selection starts from container geometry. The capacity of a cylindrical can is pi times the radius squared times the interior height, divided by 231, because a US gallon is defined as exactly 231 cubic inches; a can 24 inches tall and 15 inches across therefore holds about 18.4 gallons. The bag has to exceed the can in both directions, adding roughly 4 to 6 inches of height for the cuff that folds over the rim and a flat width near half the can circumference plus a couple of inches, so the film is not stretched taut when loaded. Undersizing produces the two classic failures: the liner slipping down inside the can, and seam tears when a full load pulls against film that has no slack. Strength is governed by film thickness in mils, thousandths of an inch, and by resin choice. Economy liners at 0.5 to 0.7 mil suit dry paper waste, standard kitchen liners at 0.7 to 0.9 mil handle wet food scraps, and contractor bags at 2 to 3 mil resist puncture from glass, screws, and broken branches. Linear low-density polyethylene delivers noticeably better tear resistance at a given gauge than conventional low-density film, which is why thin premium bags outperform thick cheap ones. Consumption estimates depend on household generation rate; EPA Facts and Figures has reported municipal solid waste generation of roughly 4.5 to 5 pounds per person per day, with recycling and composting diverting about a third of it before it reaches a bag.

The disposable plastic garbage bag is a Canadian invention of 1950. Harry Wasylyk, working in Winnipeg, developed a polyethylene liner in response to a request from the Winnipeg General Hospital for a more sanitary way to handle waste, and Larry Hansen, working at the Union Carbide plant in Lindsay, Ontario, arrived at a comparable product. Union Carbide acquired the rights and at first sold the bags to institutional customers; the company brought them to households under the Glad brand during the 1960s, displacing the older practice of lining metal cans with newspaper. The material improved faster than the concept. The catalysts developed by Karl Ziegler and Giulio Natta in the early 1950s, recognized with the 1963 Nobel Prize in Chemistry, made high-density polyethylene practical, and linear low-density polyethylene commercialized in the late 1970s gave film makers far greater tear and puncture resistance per unit of thickness, allowing thinner and cheaper bags at equal strength. Standardization followed the market rather than preceding it: ASTM International maintains specifications and test methods for polyethylene refuse bags covering dimensions, gauge, and load performance, which is what allows a 13-gallon tall kitchen bag from any manufacturer to fit the same standard can.