Former Massachusetts Gov. Mitt Romney has won most of the delegates in the Iowa Republican caucuses, edging former Pennsylvania Sen. Rick Santorum. Romney won a projected 13 delegates and Santorum won 12. Texas Rep. Ron Paul was shut out.

Twenty-five delegates were at stake in Tuesday's caucuses. The Associated Press calculates the number of national convention delegates won by candidates in each presidential primary or caucus, based on state and national party rules.

Iowa Republicans use a multi-step process to elect national delegates, starting with local caucuses. In Iowa and other caucus states, the AP uses the results from local caucuses to calculate the number of national delegates each candidate will win, if the candidates maintain the same level of support throughout the process.