A dime is 1.35 millimeters thick, according to the U.S. Mint. Each dime has 118 reeds, or indentations, along its edge. It weights 2.27 grams and has a diameter of 17.91 millimeters.
As of 2014, dimes have the smallest diameter of any U.S. coin and are also the thinnest. A penny is 1.52 mm thick with a diameter of 19.05 millimeters. It weighs 2.5 grams and has plain edges. A nickel is 1.95 millimeters thick with a diameter of 21.21 millimeters. It weighs 5 grams and has plain edges. A quarter is 1.75 millimeters thick and has a diameter of 24.26 millimeters. It weighs 5.67 grams.