Box sizes are measured by using inner dimensions unless otherwise specified. The size of your contents actually determine the inner box dimensions. These dimensions are usually listed in the following sequence: length (L) x Width (W) x Height (H). Looking at the opening of the box, measure the longest or length panel first. Using a tape measure, place it in the bottom of the box approximately one inch from the back wall and measure from left to right. Dimensions are based on the opening of an assembled box. Looking at the opening, the longer of the two sides is considered the "length". The shorter of the the two sides is the "width". The side perpendicular to the length and width is the "height" of the box
