A U.S. quarter, or quarter dollar, has a thickness of 1.75 millimeters (0.0689 inches) from front to back. The diameter, the length of a line drawn across the center of the circular coin, from edge to edge is 24.26 millimeters (0.955 inches).
A quarter is comprised of a mixture of 8.33 percent nickel and 91.67 percent copper. A single quarter weighs 5.670 grams. Quarters have been manufactured by the United States Mint since 1796. Early quarters were made of silver, which subjected the coin to clipping or shaving of the edges for the precious metal. Modern quarters have a reeded or ridged edge to protect the coin from defacement. The denomination of a quarter is 25 cents, although some rare or old coins can be quite valuable, with some worth thousands of dollars.