1 Mile of Baseball CardsA standard size Baseball card measures 3.5 inches by 2.5 inches. There are 63,360 inches in a mile. If you lay the baseball cards end by end the long way (3.5") you would need 18,103 baseball cards (a fraction of an inch over a mile) If you lay the baseball cards end by end the short way (2.5") you would need exactly 25,344 baseball cards.