9021-1(c)(2): Orders or Judgments: Interest rate post judgment
Authority for applying interest to a judgment is in 28 U.S.C. 1961. See also LBR 9021-1(c)(2).
The U.S. District Court for the Central District of California maintains information on its website that parties can use to computing interest on judgments, or post judgment interest, including a Federal Reserve Table of weekly interest rates. See link below