How many amendments does the Constitution have?

the United States Constitution has 27 amendments. The first ten, known as the Bill of Rights, were ratified simultaneously in 1791. The remaining seventeen have been ratified separately over the subsequent years, with the most recent, the 27th Amendment, being ratified in 1992.

First Amendment (1791): Protects freedom of speech, religion, press, assembly, and petition.
Second Amendment (1791): Protects the right to bear arms.
Third Amendment (1791): Prohibits the quartering of soldiers in private homes during peacetime without the owner's consent.
Fourth Amendment (1791): Protects against unreasonable searches and seizures.
Fifth Amendment (1791): Sets out rules for indictment by grand jury and eminent domain, protects the right to due process, and prohibits self-incrimination and double jeopardy.
Sixth Amendment (1791): Protects the right to a fair and speedy public trial by jury, including the rights to be informed of the accusations, to confront the accuser, to obtain witnesses, and to retain counsel.
Seventh Amendment (1791): Provides for the right to a trial by jury in certain civil cases, according to common law.
Eighth Amendment (1791): Prohibits excessive fines and excessive bail, as well as cruel and unusual punishment.
Ninth Amendment (1791): Protects rights not enumerated in the Constitution.
Tenth Amendment (1791): Limits the powers of the federal government to those delegated to it by the Constitution.
Eleventh Amendment (1795): Makes states immune from suits from out-of-state citizens and foreigners not living within the state borders; lays the foundation for sovereign immunity.
Twelfth Amendment (1804): Revises presidential election procedures.
Thirteenth Amendment (1865): Abolishes slavery and involuntary servitude, except as punishment for a crime.
Fourteenth Amendment (1868): Defines citizenship, contains the Privileges or Immunities Clause, the Due Process Clause, the Equal Protection Clause, and deals with post–Civil War issues.
Fifteenth Amendment (1870): Prohibits the denial of the right to vote based on race, color, or previous condition of servitude.
Sixteenth Amendment (1913): Allows the federal government to collect income tax.
Seventeenth Amendment (1913): Establishes the direct election of United States senators by popular vote.
Eighteenth Amendment (1919): Established the prohibition of alcohol (later repealed by the Twenty-First Amendment).
Nineteenth Amendment (1920): Prohibits the denial of the right to vote based on sex.
Twentieth Amendment (1933): Changes the date on which the terms of the president and vice president (January 20) and senators and representatives (January 3) end and begin.
Twenty-First Amendment (1933): Repeals the Eighteenth Amendment and makes it a federal offense to transport or import intoxicating liquors into U.S. states and territories where such transport or importation is prohibited by the laws of those states and territories.
Twenty-Second Amendment (1951): Limits the number of times a person can be elected president: a person cannot be elected president more than twice, and a person who has served more than two years of a term to which someone else was elected cannot be elected more than once.
Twenty-Third Amendment (1961): Provides for representation of Washington, D.C. in the Electoral College.
Twenty-Fourth Amendment (1964): Prohibits the revocation of voting rights due to the non-payment of a poll tax or any other tax.
Twenty-Fifth Amendment (1967): Addresses succession to the presidency and establishes procedures both for filling a vacancy in the office of the vice president and for responding to presidential disabilities.
Twenty-Sixth Amendment (1971): Prohibits the denial of the right of US citizens eighteen years of age or older to vote on account of age.
Twenty-Seventh Amendment (1992): Prevents any law that changes the salaries of the members of Congress from taking effect until the start of the next set of terms of office for representatives.