Take the headache out of finding a perfect-sized box for shipping items by making your own shipping boxes. An appropriate-sized box protects the item you're shipping while reducing shipping costs (smaller boxes typically cost less to ship). Shipping boxes are available from a variety of retailers and office supply stores, but you can avoid this expense by making your own shipping boxes with supplies you have on hand.
Determine the size of shipping box required. Use a tape measure to measure the length, width and height of the item you need to ship. For fragile items, add an extra inch to the measurements to account for bubble wrap or other packing material.
Jot the measurements down on a piece of paper. (To ship an item that is 8-1/4 inches wide by 10-3/4 inches long by 5-1/4 inches high, for example, a box sized 8-1/2 inches wide by 11 inches long by 5-1/2 inches high would work well).
Figure the length of cardboard required. Add the width plus the length plus the width plus the length together. (For example, 8-1/2 inches plus 11 inches plus 8-1/2 inches plus 11 inches = 39 inches). Add an additional inch to the length to serve as a tab to secure the box together. (This example requires cardboard 40 inches in length.)
Figure the width of cardboard. To determine the width of cardboard required, add the box width to the box height. (For a box that is 5-1/2 inches high and 8-1/2 inches wide, you would need a total width of 14 inches. Note the width of the box is also used to determine the size of the top and bottom box flaps [box width divided by 2 = box flap size]).
Use a large piece of cardboard or the center of a flattened cardboard box that's large enough to make the required shipping box. Measure the width and length and mark with a pencil.
Use a long straightedge to mark the outline of the box.
On a protected surface, use a utility knife and straightedge to cut along the outline of the box.
Use a tape measure and pencil to mark the fold lines. (For this example, the fold lines would be at 8-1/2 inches, 19-1/2 inches, 28 inches and 39 inches.)
Use the initial box width to determine the size of the top and bottom box flaps. (For this example, the top and bottom box flaps would be 4-1/4 inches each.)
For the top flaps, measure down from the top of the box and mark with a pencil. Use a straightedge to mark the entire length of the box.
For the bottom box flaps, measure up from the bottom of the box and mark with a pencil. Use a straightedge to mark the entire length of the box.
Begin at the top of the box and cut along the fold lines until you reach the line you just drew for the top flaps. Repeat this step for the bottom flaps.
Trim off excess cardboard at the end of the box to allow for the tab that will be used to hold the box together.
Use a metal edge to fold the box at the first fold mark. Continue this process until the box is folded at all fold marks.
Fold the box tab inward and use adhesive tape to secure to the inside of the box.
Fold in the bottom box flaps and use packing tape to secure the bottom of the box.
Place item to ship inside the box. Tape shut with packing tape. Add address—you're now ready to ship your package.