To determine proper bag size for a round container:

Circumference = Diameter x 3.14

  1. For the circumference of the bag, multiply the diameter of the container by 3.14. Divide by 2 to get the flat width. Add 1 inch for a looser fit.
  2. Add 1/2 of the diameter to the height of the container. Add 4 inches to this value for overhang. This is the total length of the bag needed.
  3. If tying bag, add 1/2 of the diameter to bag length in Step 2.

To determine proper bag size for a square or rectangular container:

  1. Add the width and length of the sides. Add 1 inch for a looser fit. This total equals the flat width of the bag needed.
  2. Add 1/2 of the shortest side to the height of the container. Add another 4 inches to this value for overhang. This is the total length of the bag needed.
  3. If tying bag rather than lining a box, add 1/2 length of the shortest side to the bag length in Step 2.