How much is a knut from Harry Potter worth?

Answer 1

Approx $0.01 (US) or £0.02 (GBP).

Currency in the wizarding world consists of three different coins. In decreasing order of value, they are: Galleon, Sickle and Knut. They are gold, silver, and bronze, respectively. According to Hagrid, there are 17 Sickles in a Galleon, and 29 Knuts in a Sickle. Around the edge of each coin is a series of numerals which represent a serial number belonging to the Goblin that cast the coin.

According to JK Rowling, the approximate value of a Galleon is 'About five [Great British] pounds, though the exchange rate varies!' . This is consistent with the "textbooks" Rowling wrote for charity (Fantastic Beasts and Where to Find Them and Quidditch Through The Ages), which states that US$250 million is equivalent to 34 million Galleons, which means that 1 Galleon ≈ US$7.35. US$7.35 was the same as about GB£5 at the time of publishing.

With this information, we can calculate the value of wizarding currency in Muggle money. The amounts shown at the beginning of this answer are approximate, and were accurate as of 1 September, 2007.

As of mid-2008 1 GBP is close to 2 USD.

Note that the Galleon/Pound rate cited by Rowling is probably that offered by Gringotts and bears no relation to the precious-metal value of Wizarding coins. The "gold coins the size of hubcaps" mentioned in reference to the Quidditch World Cup would be much larger than the British five-pound Quintuple Sovereign today sold for its bullion value of hundreds of pounds sterling (though this hubcap reference may have been an exaggeration). However, it is unclear whether the coins were Galleons, or the currency of some other Wizard community.