A federal grand jury has between 16 and 23 jurors, and at least 12 of them must vote in favor of charges before an indictment can be returned. That answers how many jurors are on a grand jury at the federal level. State grand juries vary: some match the federal range, others seat panels closer to a dozen, and voting thresholds shift from a simple majority to a supermajority depending on the state.1Legal Information Institute. Federal Rules of Criminal Procedure Rule 6 – The Grand Jury
Federal Grand Jury Size
Federal Rule of Criminal Procedure 6 sets the range at 16 to 23 members. The court summons enough qualified residents of the judicial district to fill a panel within that window.1Legal Information Institute. Federal Rules of Criminal Procedure Rule 6 – The Grand Jury
The 12-vote minimum applies regardless of how many jurors are seated that day. A panel of 23 still needs 12 yeses. A panel of 16 still needs 12 yeses. Federal grand juries meet over many weeks or months, and attendance fluctuates, so the floor guarantees that a meaningful majority stands behind any indictment. If a prosecutor cannot persuade 12 jurors that probable cause exists, no charges go forward.
State Grand Jury Sizes
State grand juries do not follow a single formula. Some states seat 23 members, mirroring the federal ceiling. Others use smaller panels of roughly a dozen or fewer. The number of votes required for an indictment also varies, with some states accepting a simple majority and others demanding a two-thirds or three-fourths supermajority.
One boundary worth knowing: not every state routinely uses grand juries at all. The Fifth Amendment’s grand jury requirement applies only in federal court and has never been extended to the states.2Constitution Annotated. Grand Jury Clause Doctrine and Practice Roughly half of all states require grand jury indictments for serious felonies. The other half let prosecutors file charges directly through a document called an “information.” Nearly every state still keeps the grand jury available as an option even where it is not mandatory, so panel sizes are defined in state law whether used often or rarely.
Grand Jury Size vs. Trial Jury Size
People often mix up grand juries with the juries they see in courtroom dramas. The counts are different, and so is the job.
Federal trial juries have 12 members by default, though the parties can agree in writing to a smaller panel.3Legal Information Institute. Federal Rules of Criminal Procedure Rule 23 – Jury or Nonjury Trial State trial juries range from 6 to 12 depending on the jurisdiction and type of case. Federal grand juries, by contrast, seat 16 to 23.1Legal Information Institute. Federal Rules of Criminal Procedure Rule 6 – The Grand Jury
The voting rules also differ. A federal criminal trial jury must reach a unanimous verdict to convict.4Constitution Annotated. Unanimity of the Jury A federal grand jury only needs 12 of its members in agreement, and state grand juries can require less than unanimity as well. Trial jurors decide guilt beyond a reasonable doubt in open proceedings. Grand jurors decide whether probable cause exists to charge someone, and they do that work in secret.5United States Courts. Types of Juries
Why the Numbers Are What They Are
A grand jury’s size reflects its role. The panel is not weighing guilt. It is screening whether the government has enough evidence to bring a case at all. A larger body spreads that screening function across more community members, and the 12-vote threshold inside a 16-to-23 panel means a prosecutor cannot squeak through on the agreement of just a handful of jurors who happen to show up.
The Fifth Amendment requires grand jury indictment for federal crimes punishable by death or by more than one year in prison, which covers essentially all federal felonies. The only constitutional carve-out is for certain military cases during wartime or public danger.2Constitution Annotated. Grand Jury Clause Doctrine and Practice Federal misdemeanors, meaning offenses punishable by a year or less, do not require a grand jury. A defendant can also waive the right to grand jury indictment in open court and agree to be prosecuted by information instead, which commonly happens during plea negotiations.6Justia. Federal Rules of Criminal Procedure Rule 7 – The Indictment and the Information
Quick Reference
- Federal grand jury: 16 to 23 jurors, 12 votes needed to indict.
- Federal trial jury: 12 jurors by default, unanimous verdict required to convict.
- State grand juries: size varies by state, from around a dozen up to 23, with voting thresholds set by state law.
- State trial juries: typically 6 to 12 jurors depending on jurisdiction and case type.
If you have been summoned and want to know what the panel you are joining will look like, the number of seats and the vote threshold are set by the rules of the court that called you: Federal Rule of Criminal Procedure 6 for federal panels, and the corresponding statute or rule in your state for state panels.