As per the reports, polls begin closing in the United States at 18:00 Eastern Standard Time (23:00 GMT) and poll closing times vary by state.
The earliest we could know whether a presidential candidate is projected to have won 270 electoral votes, is likely to be 23:00 EST (04:00 GMT). That is when polls close in California, which has the most electoral votes of any state – 55 – and that could put a candidate over the 270 thresholds.
Each state has a number of electors depending on its population. The first candidate to 270 Electoral College votes wins the presidency.