The total amount of gold that has ever been mined has been estimated at around 142,000 metric tons and arguments have been made that this amount is too small to serve as a monetary base. The value of this amount of gold is over 6 trillion dollars while the monetary base of the US, with a roughly 20% share of the world economy, stands at $2.7 trillion at the end of 2011. Even in the unlikely prospect that all mined gold could be turned into coin, a return to the gold standard would result in a significant increase in the current value of gold.