When folded flat, the box measures 6 1/2" wide, and 4 3/4" high. The box is cut in two parts. I created a file in Design Space for the Explore for the basic shapes (You can also cut them by hand)
Top shape is 9 1/2" wide and 3" tall. The two shapes on the left are the inserts for inside the box to hold all the elements. They are 5 1/2" x 1 1/2".
Here is your assembled box. Add your decorative paper and box is done. Add elements and that's it! I've made other boxes that measure 5" high by 6" wide when folded flat. I make these in 2 pieces, both measuring 5 x 6 1/2. The 1/2 " is the flap, when trimmed as above, attaches to form the box.
Hope this is information is clear and helpful. If you have any questions, just post in comments and I will try to answer.
Have a great day!