What's Inside an American Penny? Exploring Copper Content Through the Years #CoinCollector The composition of American pennies has changed over the years. Prior to 1982, pennies were made of 95% copper and 5% zinc. Due to rising copper prices, from mid-1982 onward, pennies have been primarily made of zinc (97.5%) with a thin copper plating (2.5%). This shift significantly reduced the amount of copper in each penny, making older pennies heavier and more valuable in terms of copper content compare