United States v. Booker, 543 U.S. 220 (2005), is a United States Supreme Court decision on criminal sentencing. The Court ruled that the Sixth Amendment right to jury trial requires that other than a prior conviction, only facts admitted by a defendant or proved beyond a reasonable doubt to a jury may be used to calculate a sentence exceeding the prescribed statutory maximum sentence, whether the defendant has pleaded guilty or been convicted at trial. The maximum sentence that a judge may impose is based upon the facts admitted by the defendant or proved to a jury beyond a reasonable doubt.