The gold aureus seems to have been a "currency of account", a denomination not commonly seen in daily transactions due to its high value. Numismatists think that the aureus was used to pay bonuses to the legions at the accession of new emperors. It was valued at 25 denarii.

1 gold aureus = 2 gold quinarii = 25 silver denarii = 50 silver quinarii =100 bronze sestertii = 200 bronze dupondii = 400 copper as = 800 copper semisses = 1600 copper quadrans

Even after the denarius (plural: denarii) was no longer regularly issued, it continued to be used as an accounting device and the name was applied to later Roman coins in a way that is not understood. The lasting legacy of the denarius can be seen in the use of "d" as the abbreviation for the British penny (denny?) prior to 1971. It survived in France as the name of a coin, the denier. The denarius also survives in the common Arabic name for a currency unit, the dinar used from pre-Islamic times, and still used in several modern Arabic-speaking nations. Currency unit in former Yugoslavia and nowadays in Serbia is dinar which has its origins also in the Latin word of denarius. The Italian word denaro, Spanish word dinero, the Portuguese word dinheiro, the Slovenian word denar and the Catalan word diner -all meaning money- are also derived from Latin "denarius".