Around 97% of Scots are registered to vote, making it the largest electorate the country has ever known.
So what other key facts surround the Scottish referendum?
Out of the 4,285,323 people registered to vote, 118,640 joined the ranks in just the last month, while 789,024 will be voting by post.
Scotland has a £150bn (€190bn, $244bn) economy, but owns £100bn worth of UK debt.
Meanwhile, Scotland enjoys the lowest unemployment rate of the Union's four nations.