Cubic Feet Calculator

Multiply length × width × height in feet. If a dimension is in inches, divide it by 12 first. A box 2 ft × 2 ft × 3 ft is 12 cubic feet.

A cubic yard contains 27 cubic feet, so divide cubic feet by 27 to convert to cubic yards.

Measure the inside of each compartment in inches — height, width and depth — multiply the three, then divide by 1,728, since a cubic foot is 1,728 cubic inches. Add the fresh-food and freezer compartments together. A 30 × 28 × 24 inch interior works out to about 11.7 cubic feet.

Multiply the floor length by the width by the ceiling height, all in feet. A 12 by 14 room with an 8-foot ceiling holds 1,344 cubic feet. This is the figure heating, cooling and air-purifier sizing use — floor area alone ignores how much air a tall ceiling adds.

Multiply the bed area in square feet by the depth in feet. At the usual 3-inch depth that is area × 0.25. A 20 by 4 foot bed is 80 ft², so 80 × 0.25 = 20 cubic feet — ten of the standard 2-cubic-foot bags.

Multiply length by width by depth in feet. For a raised bed, use the fill depth rather than the box height — most beds are filled an inch or two short of the rim. An 8 by 4 bed filled 10 inches deep is 8 × 4 × 0.833, or about 26.7 cubic feet.