Answer? When you are talking about the value of the U.S. Government owned gold reserve.
The actual gold bullion, minted coins, blanks and other gold materials are measured by the ounce for the purpose of inventorying the stash that backs our currency. However, the Department of the Treasury reports the Book Value of all that 24k goodness at the values stated in 31 USC § 5116-5117. The statutory rate is $42.2222 per Fine Troy Ounce of gold. The market value of the gold reserves, based on the London Gold Fixing as of September 29, 2017, was $335.5 billion.
Historic City News editor Michael Gold obtained the most recent, current status report while visiting the US Mint in Denver.
Status Report of U.S. Government Gold Reserve
Current Report: October 31, 2017
Fine Troy Ounces
|Gold Coins, Blanks, Miscellaneous||2,857,048.156||120,630,858.67|
|Mint-Held Gold – Deep Storage|
|Fort Knox, KY||147,341,858.382||6,221,097,412.78|
|West Point, NY||54,067,331.379||2,282,841,677.17|
|Subtotal – Deep Storage Gold||245,262,897.040||10,355,539,085.76|
|Mint-Held Treasury Gold – Working Stock|
|All locations – Coins, blanks, miscellaneous||2,783,218.656||117,513,614.74|
|Subtotal – Working Stock Gold||2,783,218.656||117,513,614.74|
|Grand Total – Mint-Held Gold||248,046,115.696||10,473,052,700.50|
|Federal Reserve Bank-Held Gold|
|Federal Reserve Banks – NY Vault||13,376,987.724||564,805,851.07|
|Federal Reserve Banks – display||1,993.321||84,162.40|
|Subtotal – Gold Bullion||13,378,981.045||564,890,013.47|
|Federal Reserve Banks – NY Vault||73,452.066||3,101,307.82|
|Federal Reserve Banks – display||377.434||15,936.11|
|Subtotal – Gold Coins||73,829.500||3,117,243.93|
|Total – Federal Reserve Bank-Held Gold||13,452,810.545||568,007,257.40|
|Total – U.S. Government Gold Reserve||261,498,926.241||$11,041,059,957.90|
Deep Storage: That portion of the U.S.Government-owned gold bullion reserve which the Mint secures in sealed vaults that are examined annually by the Treasury Department’s Office of the Inspector General and consists primarily of gold bars.
Working Stock: That portion of the U.S. Government gold reserve which the Mint uses as the raw material for minting congressionally authorized coins and consists of bars, blanks, unsold coins and condemned coins.
The gold reserve held by the Department of the Treasury is partially offset by a liability for gold certificates issued to the Federal Reserve Banks at the statutory rate, which Treasury may redeem at any time.