How many terms may a US president be elected to?

Under the 22nd Amendment, a US President may be electedto two at most 4-year terms of office. However, a Vice President who succeeds an elected President and serves more than two years of that President's term may only be elected to one term. A Vice President who succeeds an elected President and serves two or fewer years of that person's term of office may be elected twice more.

This effectively limits a President to a maximum of 10 years in office (two and one-half terms).

The actual text of Amendment 22, Section 1(amendment passed 1947, ratified 1951)"No person shall be elected to the office of the President more than twice, and no person who has held the office of President, or acted as President, for more than two years of a term to which some other person was elected President shall be elected to the office of the President more than once. But this article shall not apply to any person holding the office of President when this article was proposed by the Congress, and shall not prevent any person who may be holding the office of President, or acting as President, during the term within which this article becomes operative from holding the office of President or acting as President during the remainder of such term."
Now, they can only serve two 4-year terms.