Iran is cutting the oil price on which it bases its next budget to $40 a barrel, the semi-official Fars news agency quoted Finance and Economy Minister Ali Tayyebnia as saying on Thursday.
"We will revise the oil price in the budget from $72 per barrel to $40... The drop ...will not bring us to our knees and we plan to turn it into opportunities," Tayyebnia said.
Plummeting oil markets have put huge pressure on Iran's state finances, already stretched by Western economic sanctions over its disputed nuclear program, and the country has supported calls from Venezuela for a production cut by the OPEC group.
Its next fiscal year starts on March 21.
In December, President Hassan Rouhani presented an 8,400 trillion rial ($312 billion) budget proposal to parliament.
Since then, however, already falling global oil markets have sunk further and Brent crude, trading at about $69 barrel in early December, is now below $50.
Fars did not give any new revenue projections based on $40 oil or say how the budget might be revised.