A face cord is an informal unit of volume for stacked firewood, sometimes called a rick.
Width and height is typically the same as a cord, but the depth can vary. The front face is the same as a cord (4'x8'), hence the name. The depth is generally commonly 16" (for use in residential fireplaces) but can be anything from 12 inches to 32 inches.
This results in a volume of 32 to 85 cubic feet. Several states only allow wood to be sold by the cord or fractions of a cord, to avoid confusion among consumers.
The wood should stacked "racked and well stowed" - meaning stacked so that the wood is parallel, and air gaps are minimized. It should not be cross-stacked (alternating directions), as this adds considerable empty space to the stack.
4 feet x 8 feet x 12 inches = 1/4 cord (32 cubic feet)
4 feet x 8 feet x 16 inches = 1/3 cord (42.66 cubic feet)
4 feet x 8 feet x 24 inches = 1/2 cord (64 cubic feet, 1.8 cubic meters)
4 feet x 8 feet x 32 inches = 2/3 cord (85 cubic feet)