FACTBOX-Delegate counts for US presidential candidates

Feb 6 ,(Reuters) - Delegates will be the key to selecting the Democratic and Republican nominees for U.S. president at national conventions in August and September before the presidential election on Nov. 4.

Voters choose the delegates state-by-state.

While the Feb. 5 contests did not clinch the nomination for any candidate, those who did well may be on the way to victory since half the Democratic delegates and more than 40 percent of the Republicans were to be chosen on "Super Tuesday."

Delegates are still being counted but these are the total number of delegates awarded so far in nominating contests to the leading candidates:

DEMOCRATS (total needed for nomination 2,025)

-Barack Obama 838

-Hillary Clinton 834

REPUBLICANS (number needed for nomination 1,191)

-John McCain 720