1964 and later United States quarter-dollar coins weigh 5.670 grammes, or 0.200 ounces. Since its introduction in 1796, the weight of the quarter has varied slightly.
According to the stipulations of the Mint Act of 1792, the original quarters weighed 6.74 grammes or 0.20 ounces. These coins were struck between 1796 and 1838. The coins that followed were redesigned to contain more silver and ranged in weight between 6.68 and 6.22 grammes (0.23 and 0.20 ounces). Quarters issued between 1892 and 1964 feature varied designs and metal compositions, weighing 6.25 grammes or 0.22 ounces and weighing 6.25 grammes or 0.22 ounces, respectively.