Shipping box sizes: standard corrugated box dimensions

How box sizes are written

Corrugated boxes are listed by their inside dimensions in the order length × width × depth. Length and width are the opening, length the longer of the two, and depth is the height from the opening to the bottom; Uline lists its boxes this way and notes that they open along the length. So a 12 × 9 × 6 in box opens 12 × 9 in and is 6 in deep, and a 12 × 6 × 9 in box is a different, taller box.

The outside is larger by the board on every side: Uline gives its 12 × 12 × 12 in box an outside size of 12⅜ × 12⅜ × 12⅝ in. Measure the product with its packing and allow room for cushioning on every side, then check the outside size too if a carrier, a shelf or a pallet limits it. Uline’s stock boxes are 200 lb test corrugated; heavier or fragile goods need a stronger board, which the box maker can advise on.

Printing a shipping box

Most shipping boxes are regular slotted containers (RSC): four side panels in a row with a glue flap, and flaps above and below that meet in the middle. Flat, that blank is about twice the length plus twice the width across, plus the glue flap, and the depth plus the width tall, since each flap is half the width deep. The box maker supplies the dieline for the style, inside size and board; place the artwork on it at 100%: see setting up a dieline.

Long runs are usually printed flexo straight onto the board, in one or two spot colors, often on kraft; short runs and full color are printed digitally. Flexo on corrugated thickens fine lines and fills in small reversed type, so keep the artwork bold and each color a spot color: see spot colors and lines too thin to print. Leave a plain area of at least 4 × 6 in for the shipping label, and keep artwork off the center seam of the flaps, where the tape goes. For branded boxes the customer opens, see mailer box sizes.

Questions

What are standard shipping box sizes?

Stock sizes run from small cubes to large cartons; common everyday ones include 8 × 6 × 4, 12 × 9 × 6, 12 × 10 × 8, 12 × 12 × 12, 16 × 12 × 8 and 18 × 12 × 12 in, inside length × width × depth. Suppliers stock many sizes in between, so choose the smallest that fits the product and its packing.

In what order are box dimensions listed?

Length × width × depth, measured inside. Length and width are the opening (length the longer side) and depth is the height. A 12 × 9 × 6 in box opens 12 × 9 in and is 6 in deep.

What size is a USPS Medium Flat Rate Box?

The top-loading Medium Flat Rate Box is 11 × 8½ × 5½ in inside (11¼ × 8¾ × 6 in outside), and the side-loading one is 13⅝ × 11⅞ × 3⅜ in inside, in USPS’s quick reference. They are USPS’s own boxes, so they can’t be custom printed.

What size is a shipping box side in pixels?

At 300 ppi, the long side of a 12 × 9 × 6 in box (12 × 6 in) is 3600 × 1800 pixels, of a 16 × 12 × 8 in box 4800 × 2400, and one face of a 12 in cube 3600 × 3600. Shipping box artwork is usually vector, in one or two spot colors.

If the printer sends the file back

• “The artwork doesn’t fit our dieline”
• “Convert the spot colors to CMYK”
• “Some lines are too thin to print”
• “There’s no white ink layer”
• “Fonts aren’t embedded, please outline them”