The rate of interest used in calculating the amount of post-judgment interest is the weekly average 1-year constant maturity (nominal) Treasury yield, as published by the Federal Reserve System each Monday for the preceding week (unless that day is a holiday in which case the rate is published on the next business day). In cases where the judgment date is the same as the release date, select the prior week’s release rate; interest rate releases are considered to be issued at the close of business on the date of release.
The post-judgment interest rate for judgments entered from July 30, 2018 through August 5, 2018 is: 2.44%.
2018 rates may be found here.
Historic rates from 2017 - 2000 can be found here.
Rates for judgments entered prior to December 21, 2000 are based on the auction of 52-week T-bills. Historical rates for judgments entered prior to December 21, 2000, are listed here.
Information about rates can be found at the Federal Reserve: http://www.federalreserve.gov/releases/H15/Current