Cardboard Box Template : 7 Steps - Instructables
Step 3: Draw & Cut-out Your Pattern. Make sure the cardboard sheet is at least as big as the dimensions on the template (A & B). If you can't find corrugated material big enough to make a box in one piece, use the template called "2-Piece Box" & use 2 or more sheets to make one box (see Step # 6: "2-Piece Box").