"There is no option short of EU membership that is as good as being in the EU," Sturgeon said as she presented an analysis of possible future ties with the bloc.
"This is about degrees of what does the least damage to our economy," she told journalists in the Scottish capital Edinburgh.
According to the new analysis, Scotland's GDP would plunge 8.5 per cent by 2030 if no deal is reached with Brussels and Britain has to fall back on World Trade Organisation rules.
Sturgeon said the impact study served as "compelling" evidence that Britain should remain part of the single market, if it is not possible to stay an EU member as her Scottish National Party would like.
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She predicted a majority of British lawmakers would support single market membership, despite Prime Minister Theresa May ruling it out largely owing to its condition of continuing free movement of people.
Sturgeon accused the British government of a "reckless and irresponsible approach" in the negotiations so far, arguing London had entered talks with unachievable aims, and urged the government to put single market membership back on the table.
The SNP leader has previously pushed for a second referendum on Scottish independence from Britain, as a result of Brexit, and said Sunday a decision on holding another vote would be taken when the shape of the EU deal becomes clearer.