More than a week after Election Day, control of the House of Representatives has yet to be decided. Out of the 435 seats in Congress’s lower chamber, 12 have yet to be called. How many of these seats — most of them concentrated in slower-counting Western states such as California and Arizona — does each party need for a 218-seat majority?

Votes are still being counted in key U.S. House races, but it's looking more likely that President-elect Donald Trump will take office with the Republicans holding majorities in both chambers of Congress.