Most medieval and renaissance era currency had intrinsic value due to being made from rare metals. Gold coins, for example, were usually worth their weight in gold. To keep people from constantly weighing or melting coins to determine their true worth, reputable coins would be stamped by an official government. Forgeries were certainly possible, but the punishment would be severe. Over time coins tended to be minted from less valuable metals, reducing their value but allowing for more coinage in circulation. At any rate, the exchange rate was set by comparing the value of the two coins and working from there. If two gold coins weighed the same they should have an equal exchange rate, and so forth. Most people would not have many coins to speak of to their name, much less foreign coins, so this kind of exchange likely only took place at high levels among traders or royalty.

The Pfennig was the smallest coin minted by the Holy Roman Empire. Charlemagne decreed that a pound of silver would be used to make 240 pfennigs. Therefore, each pfennig could be expected to weigh 1/240 a pound, and be pure silver. As the grip of the Emperor slipped, local lords began minting their own pfennigs with lower purity as a way to attempt to increase their own wealth; however, over the long term this just devalues pfennigs everywhere. By the 1600's they contained only traces of silver, or a silver coating, and were worth very little.