15 American vice presidents went on to become president. Of those, 8 succeeded after a president died or resigned, and 6 were elected to the presidency in their own right; 1 more, Gerald Ford, became president after a resignation without ever being elected vice president first.

Quick breakdown

  • 15 total vice presidents later became president.
  • 8 first took office through succession after a death.
  • 6 were later elected president on their own.
  • Gerald Ford is the special case, because he became president through succession without winning either the vice presidency or the presidency in a national election.

Simple answer

So the cleanest answer is: 15.

TL;DR

The U.S. vice presidency has been a launchpad to the Oval Office, but it has not guaranteed the jump; only 15 vice presidents ultimately became full presidents.