By now, you've likely seen hundreds of iterations of the electoral college map, lighting up our country in red and blue states. But now that we're down to the wire, exactly how many electoral votes do the candidates need to win the election? Either Hillary Clinton or Donald Trump [1] will secure the election tonight by winning 270 electoral votes. The 270 votes it takes to win the presidential election come from the 538 votes given to the country's 435 representatives, 100 senators, and three electors from the District of Columbia.

The number of electoral votes that each state gets depends on how many members of Congress they have. Since representatives in the House reflect the population size of the state, heavily populated states have more electoral votes. The candidate who wins the popular vote of a state wins all of the electoral votes (with the exception of Nebraska and Maine, where the electoral votes can be split between candidates).

While some states predictably always vote either Democratic (blue) or Republican (red), "swing states" are states that vary year to year and are incredibly important to the election process. There are 11 swing states: Colorado, Florida, Iowa, Michigan, Nevada, New Hampshire, North Carolina, Ohio, Pennsylvania, Virginia, and Wisconsin.

In the last election in 2012, President Barack Obama won the presidency with 332 electoral votes, while Mitt Romney only earned 206 votes. Obama won swing states Florida, Virginia, Colorado, Ohio, Pennsylvania, New Hampshire, Wisconsin, Michigan, and Nevada, securing his presidency for another four years.

Presidential candidates Donald Trump and Hillary Clinton will have to hope they win in at least some of those swing states in order to earn 270 votes and win the presidency tonight.