These swing states will likely decide the U.S. presidential election

Winning the U.S. election is as simple as winning the majority of the 538 electoral votes available across the country's 50 states and the District of Columbia.

The number of electoral votes a state has is proportional to its population, and in general, the candidate who gets the most votes in a state gets all of its electoral votes.

Based on polling and vote histories, the results of many states are a foregone conclusion – with 30-point victories in the past two elections and a 30-year history of going to the Democrats, California's 54 electoral votes, for example, are almost certainly going to be won by U.S. Vice-President Kamala Harris.

Analysts like the Cook Political Report see 226 electoral votes likely going to the Democrats and 219 to the Republicans.

That leaves 93 electoral votes considered to be a toss-up, spread across seven states that could swing either way on election night. Those states are Pennsylvania (19 electoral votes), Georgia (16), North Carolina (16), Michigan (15), Arizona (11), Wisconsin (10) and Nevada (6).

These swing states will most likely determine the path to the presidency, with candidates needing to win some combination of votes to get them across the 270 mark to secure a majority.

The math

There could very well be some surprises after the votes come in – Iowa, for example, hasn't been considered a swing state, but a last-minute poll has pegged Harris ahead of Donald Trump, adding some uncertainty to his firm grasp on the state.

Assuming, though, that things shake out as expected, Harris needs to secure 44 electoral votes from the swing states to reach 270 and become the next U.S. president, while Trump needs 51 of those votes.

That could come from any number of state combinations, but Pennsylvania, the largest of the swing states with 19 electoral votes, is going to be a key factor.

If Trump wins Pennsylvania, for example, winning Georgia and North Carolina (and the other states assumed to be going in favour of the Republicans) would be enough to win the election.

The picture will become clearer as the evening goes on – although in 2020, during the pandemic, the large number of mail-in ballots and close races meant many key states weren't decided until days after the election.

Below is a breakdown of each of the swing states, their vote history and when we can expect to start seeing results after polls close.