There are 3 million coins in circulation in the Seven Kingdoms of Westeros:

There are 3 million coins in circulation in the Seven Kingdoms of Westeros: 750,000 debased Lannister-minted dragons, each of which contained 7/12 ounces of silver, and 2,250,000 government-minted stags, each of which contained 4/9 ounces of silver. Both coins represented 7 stars, so the money supply was 21 million stars. The price of bread was 2/5 = 0.4 stars per loaf. Bread could also be purchased using raw silver at a rate of 27 loaves per ounce.