How to make it

Print at 100% (Actual size), not Fit to page.
Cut the solid lines and crease the dashed ones against a ruler.
Fold the base and the lid, glue the tabs inside the side walls, stack the cards in and slide the lid on.

A 14 pt card is 0.356 mm thick, so 100 stand 36 mm tall; the box adds 2 mm over them.
US cards are 3.5 × 2 in; European ones are 85 × 55 mm, a little narrower and taller.
Both boxes for 100 and the tray for 250 print on one Letter or A4 sheet.

Ready-made sizes and their sources

Each size starts from a published one, with the room its box adds.

Size	Made for	Box inside	Source
100 business cards	3.5 × 2 in cards (US standard), 14 pt (0.356 mm) thick	3.62 × 2.12 × 1.48 in (width × depth × height)	4OVER4
100 cards, 85 × 55 mm	85 × 55 mm cards (European size), 14 pt (0.356 mm) thick	3.46 × 2.28 × 1.48 in (width × depth × height)	4OVER4
250 cards on edge	3.5 × 2 in cards (US standard), 14 pt (0.356 mm) thick	3.62 × 3.62 × 1.57 in (width × depth × height)	4OVER4

Sources

4OVER4, Business Card Sizes Around the World and Why They Differ, read 2026-10-25: “The US standard business card is 3.5 x 2 inches, which is 89 x 51 mm … European 3.346 x 2.165 85 x 55”
4OVER4, How thick is 14-point?, read 2026-10-25: “So a 14-point stock is 0.014 inches, or about 0.356 mm, thick. It is the everyday standard for coated business cards”