In the US Electoral College, a candidate needs at least 270 out of 538 electoral votes to win the election.

Each state is allocated a certain number of electoral votes based on its population. Some states consistently favour one party, while “battleground” or “swing states” can shift, making them crucial in deciding the election.

This election features seven battleground states, totalling 93 electoral votes: Pennsylvania (19), Georgia (16), North Carolina (16), Michigan (15), Arizona (11), Wisconsin (10), and Nevada (6).

How can Kamala Harris win?

Harris is projected to secure at least 226 electoral votes from 19 states and the District of Columbia, with major contributions from California (54), New York (28) and Illinois (19).

To reach 270 electoral votes, Harris will need at least 44 of the 93 battleground votes.

The easiest path for her would be to win Pennsylvania (19), Georgia (16) and North Carolina (16), securing 51 electoral votes and a Harris presidency. However, at the moment, she is trailing Trump in all three, according to the FiveThirtyEight average of polls – Pennsylvania only very marginally, and Georgia and North Carolina by slightly bigger margins.

Mathematically, Democrats have 11 possible ways in which Harris could get to 270 Electoral College votes by winning just three of the seven battleground states, and another nine ways by winning four states. Winning five or more battleground states would secure the presidency for either candidate.

Here’s the combination of three or four swing states Harris would need to win to get to 270:

How can Donald Trump win?

Republicans are projected to secure at least 219 electoral votes from 24 states nationwide, with major contributions from Texas (40), Florida (30) and Ohio (17).

To reach 270 electoral votes, Trump will need at least 51 of the 93 battleground votes.

Just like the Democrats, the easiest path for him is to win Pennsylvania (19), Georgia (16) and North Carolina (16), securing 51 electoral votes and bringing the Republicans up to exactly 270 electoral votes to win the presidency. He currently leads in all three states, per poll trackers.

If Republicans do not win all of those three states, then they must win at least four out of the seven battleground states to secure the presidency. Mathematically, Republicans have 20 four-state winning combinations.

What happens if Harris and Trump end in a tie?

There are three scenarios in which Harris and Trump could both reach 269 electoral votes.

This could occur if there are no surprises, with Harris and Trump securing their 226 and 219 electoral votes respectively, and the following outcomes in the battleground states:

Scenario 1:

Democrats win:
Georgia (16), Arizona (11), Wisconsin (10) and Nevada (6)

Republicans win:
Pennsylvania (19), North Carolina (16) and Michigan (15)

Scenario 2:

Democrats win:

Georgia (16) North Carolina (16) and Arizona (11)

Republicans win:
Pennsylvania (19), Michigan (15), Wisconsin (10) and Nevada (6)

Scenario 3:

Democrats win:
North Carolina (16), Arizona (11), Wisconsin (10) and Nevada (6)

Republicans win:
Pennsylvania (19), Georgia (16) and Michigan (15)

If any of these outcomes occur, then a contingent election takes place in which the US House of Representatives decides the winner.

Each state’s delegation in the House would cast one vote, and a candidate must receive a majority (26 out of 50) of the state delegation votes to win.

The US Senate would then choose the vice president with each senator casting one vote and a simple majority (51 votes) required to win.

The graphic below highlights the winning combinations for each candidate.