Your federal election guide of seats to watch as vote counting begins and polls close

Tonight's the night — we'll soon know who Australians have chosen to govern for the next three years.

Opinion polls have drifted in Labor's direction throughout the campaign, but we're much more politically fragmented than we used to be.

Both major parties are hoping to win at least 76 seats, giving them a majority in the 150-seat parliament.

But it could be that neither gets there. We could be looking at which independent and minor party candidates are elected and who they'd back in parliament before we know who will form government.

The electorate is complicated these days. There could be surprises and it could take some time for the picture to become clear.

There are many more fascinating contests too, all detailed in Antony Green's election guide.

Make sure you've got a fridge full of snacks, your laptop or phone is fully charged and ready to keep up with the live results, and that by 5:30pm AEST your TV is turned to the ABC.

Here's your quick guide to what to watch for tonight.

When does counting start?

Voting ends at 6pm, local time, at sites across the country.

The first votes we saw came from Norfolk Island, which is in an even earlier time zone.

The few hundred votes cast from Norfolk Island voters are counted in the ACT electorate of Bean. Last election, it was the first place to report, just after 6pm.

On the mainland, the very first polling places to report results will probably be from regional seats with smaller polling places. Don't expect them to be representative of the nation.

Early voting has changed election night

Before election day today, a lot of us had already voted. The AEC says more than 6.77 million people cast a pre-poll vote, another 1.64 million completed postal votes and 155,000 voted with a mobile team.

That's about 8.5 million people — almost half the electoral roll — who've already cast their ballots.

The numbers of early voters have been trending upwards for years now and they are making predicting the winner on election night a bit trickier.

Early votes are cast in much larger polling places, meaning they take longer to count and be reported. Those votes, like the votes cast today, will be counted from 6pm, local time.

In many seats, we'll need to wait until figures from the early voting centres are reported in order to be able to say who has won.

Don't be surprised if, once all the election-day votes have been counted, there's a bit of a gap while we wait for the early votes to come through.

When will we know how long counting will take?

In every polling booth, staff from the Australian Electoral Commission (AEC) conduct the same process.

First, they sort, count and report the first-preference votes for each candidate. In some cases, the winner is immediately clear from just those figures.

But most of the time, we also need to know the preference count in the seat.

Before voting is complete, the AEC secretly predicts which candidates are most likely to finish in each seat's top two. Once the counting of first preferences is complete, it then distributes all the vote preferences between these top two candidates.

This helps maximise the chances of media organisations such as the ABC being able to predict the winner on election night.

If it turns out that the AEC isn't counting preferences for the correct two candidates, it will recount the preferences after election night, and we won't use them on the ABC.

In the days after election day, all counts are checked and re-checked.

Where should I look for early hints on the outcome?

One of the first places we'll be looking for clues as to a likely result is in Australia's two biggest cities — Melbourne and Sydney.

Victoria and New South Wales have more than half the seats in parliament between them, including some of the country's most marginal.

The Coalition is putting a lot of hope in picking up a swag of seats in outer-suburban Sydney and Melbourne. If it isn't picking up many seats in Melbourne, it will be very difficult for the Coalition to become the largest group in parliament, let alone get close.

Watch how the party is going in seats such as McEwen and Bruce in Melbourne, and Parramatta and Werriwa in Sydney.

If Labor can minimise the losses here, it has a shot of remaining in majority government.

We'll also start to get a sense of how well the crossbench — that is, independent and minor party members of parliament — is holding up, and whether any are at risk of being defeated.

For example, we will be interested to see if the primary vote for inner-city independents such as Monique Ryan in Kooyong and Allegra Spender in Wentworth is strong, or is the Liberal Party regaining ground it lost three years ago.

And could more independents join them? The seats of Bradfield in Sydney, Cowper on the mid-north coast of NSW, and Wannon in regional Victoria are seen as some of the best prospects for independent candidates.

What about Queensland?

Further north, there aren't many opportunities for the Coalition to pick up seats. It already holds all but five of Queensland's electorates. It would love to win the seat of Blair, held by Labor with a 5.2 per cent majority.

Despite the Coalition's dominance in Queensland, there are a few seats Labor is hoping to flip. And if successful, the pay-off could be significant.

Queensland is a state to watch early for clues that might tell us if Labor has a chance of winning a majority.

If Labor is tracking well in seats such as Leichhardt in the far north, or Bonner in Brisbane, and the party isn't losing lots of seats elsewhere, majority government could be on the cards.

The Greens are defending three Queensland seats: Brisbane, Griffith and Ryan, all of which the major parties would love to pick up.

Labor has also been talking a big game on Opposition Leader Peter Dutton's seat of Dickson, where a prominent independent candidate is also running. That would be a big result if it happened.

If Dutton is in trouble in his seat, which he holds by just 1.7 per cent, it's also bad news for the Coalition more broadly.

There are a few seats to watch on central time

There are fewer seats on offer in South Australia and the Northern Territory, but in an election such as this, every seat could matter.

In SA, the Liberal Party wants to win back the seat of Boothby in Adelaide's southern suburbs.

In the east of the city, Labor is hoping to make inroads in Sturt. That was previously held by senior Liberal Christopher Pyne. Labor is hoping its strength in the state and the relatively lower profile of current MP James Stevens might help it flip the seat.

There are just two seats in the NT, Solomon and Lingiari.

Lingiari takes in virtually all of the territory, except Darwin. It is also the more marginal seat, held by just 1.7 per cent by Labor. A low turnout in remote Indigenous communities could help the Coalition in Lingiari, and it feels buoyed by the fact that Labor no longer holds any seats in the territory parliament within Solomon.

Western Australia continues to be important

It was the state of Western Australia that delivered big time for Labor three years ago.

It picked up four seats in the west, with a statewide swing of more than 10 per cent.

Labor wouldn't have a majority now without it.

So tonight, Labor is hoping to hold back the Coalition from reclaiming those seats: Hasluck, Tangney, Pearce and Swan.

There's also the new seat of Bullwinkel, which is notionally held by Labor based on past voting patterns. It's being contested by Labor, the Liberals, and the Nationals, so it could be an interesting count to watch.

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