One penny (U.S.) is 1.55 mm or .061 inches thick. One million pennies are 1,550,000 mm or 61,023.622 inches tall, stacked one atop another. 1,550,000 mm = 1,550 m = 1.5 km 61,023.622 inches =...
A pile of one million British one penny pieces minted in copper plated steel would be approximately 1,650m (5,413ft) tall, because each coin is 1.65mm (0.065in) thick.