FACTBOX: Delegate counts for presidential candidates

(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 November 4.

Voters choose the delegates state-by-state.

While the February 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 here are the total number of delegates awarded so far in nominating contests so far to the leading candidates:

DEMOCRATS (total needed for nomination 2,025)

-Hillary Clinton 834

-Barack Obama 838

REPUBLICANS (number needed for nomination 1,191)

-John McCain 720

-Mitt Romney 256

-Mike Huckabee 194

HOW DELEGATES ARE AWARDED:

Democrats distribute delegates in proportion to their vote statewide and in individual congressional districts. That means candidates can come away with big chunks of delegates even in states they lose.

In contrast, most Republican contests are winner-take-all when awarding delegates, meaning Tuesday's victories by Sen. John McCain give him a commanding lead.

In addition to those elected state-by-state, a certain number of delegates at the conventions are set aside to be members of Congress, elected state officers and other leading party officials. These super delegates are not committed to any particular candidate, therefore they can back anyone they choose.

Source of Delegate Count: msnbc.com

(Compiled by JoAnne Allen and Deborah Charles, Editing by Bill Trott)