If you mean for a constitutional convention to propose amendments(s) to the Constitution, 2/3 of the state legislatures. As there are 50 states, 33 would be needed for the convention to be called.
Forty-nine states have applied for an Article V Convention (what is often called a "Constitutional Convention"), submitting more 700 applications. Article V does not permit the calling of a "constitutional convention" only a "convention for proposing amendments."
Whenever two thirds of both Houses shall deem it necessary, shall propose Amendments to this Constitution, or, on the Application of the Legislatures of two thirds of the several States, shall call a Convention for proposing Amendments.
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twelve
5
12 by AJ
12
9 states 9 states
5
9 states were needed to ratify the Constitution
9 states are needed to ratify the constitution
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