The average price ratio of silver to gold during the 20th century was approximately 47 to 1, according to Gold Eagle, an online precious metal investment research platform. This average does not readily indicate the significant fluctuation the ratio underwent during that century.
At its highest point, the silver to gold price ratio was at 96 to 1 in 1940; during economic turbulence in 1918 and 1970, it reached lowpoints below 20 to 1. Prior to the latter third of the 19th century, this ratio changed very little, averaging approximately 17 to 1. The passage of the Coinage Act of 1873 by the U.S. Congress demonetized silver, sending the ratio into significant periodic fluctuation.