How much is a farthing worth?

Under the now-obsolete £sd (or "Pounds - Shillings - Pence") monetary system in Britain, there were 12 pennies (or "pence") to the shilling and 20 shillings to the pound. A penny was thus 1/240th of a pound. In turn, there were 4 farthings to the penny. Thus, a farthing was worth 1/960th of a pound. The pound is worth (as of May 5, 2011) US$1.65 - the face value of a farthing (if it still circulated) would thus be about 1/5th of a US cent. As a point of information, although the British pound went decimal (100 new pence to the pound) in 1968, the last farthing had been minted in 1956.

From a metal standpoint, post-1837 farthings probably contains (at current prices) about 2-3 cents of copper.

From a numismatic standpoint, the value would depend on the date and condition of the coin - it could range from a few cents to a few thousand dollars.