The possibility of a Scottish referendum has been on Sturgeon's agenda since the UK voted to leave the European Union in June last year.
But while the UK as a whole voted to leave, nearly two-thirds of Scotland's electorate sought to remain.
Questioned on whether autumn 2018 would be a likely date for a referendum she told the BBC: "Within that window. I guess when the sort of outline of a UK deal becomes clear on the UK exiting the EU, I think would be the common sense time for Scotland to have that choice, if that is the road we choose to go down.
Sturgeon has previously spoken of her desire to seek a deal for the EU with Scotland and allow voters their say on a post-Brexit UK.
She has also been outspoken of her determination to keep the country in the EU.
Sturgeon's comments come as the British government gets ready to trigger Article 50, allowing formal negotiations to begin on exiting the EU.
A second referendum on Scottish independence would require permission from Westminster -- and such a request could prove difficult.
British Prime Minister Theresa May warned last week
that she would resist any clamor for such a demand, telling a Glasgow conference that such a move would lead to a "looser and weaker union."
On Thursday, a spokesman for May rejected calls for a referendum, labeling the discussion around it a "distraction."
"Our position on the issue of the referendum is well established," said the spokesman.
"The question is: Should there be a second referendum? No, we don't believe that there should.
"The (previous Scottish independence) referendum was held only in 2014. It was a fair, decisive and legal vote. Both sides agreed to abide by that and we think that both sides should. The continued discussion around a second referendum is a distraction."
In the September 2014 referendum Scotland voted to reject independence by 55% to 45%.