Hanoi spent around VND266 billion (US$13.64 million) on the ten-day anniversary celebration in October, the city said Wednesday, replying to questions raised during the National Assembly session last month.
Officials had earlier failed to give a specific number while denying rumours they had overspent vastly.
The money was used for protocol events, campaigns, cultural activities and gifts for the celebration from October 1 to 10, the People's Committee said during the ongoing meeting with the city's legislators.
Hoang Manh Hien, vice chairman of the committee, said the government had set a target of spending VND350 billion on the celebration.
The plan was to give more than VND252 billion to campaigns and cultural and artistic activities, but they only cost a little more than VND250 billion; VND10 billion was earmarked for protocol activities of which VND7.6 billion was used up; and of VND9.2 allocated for gifts, the actual expenditure was VND8.2 billion, Hien said.
He said efforts were made to save as much as possible for all activities, avoiding mistakes.
Local media had earlier reported rumors that anniversary organizers had spent VND4-5 trillion (US$205-257 million) on the celebrations.
Lawmaker Nguyen Lan Dung had sent a note to the Finance Ministry during the NA meeting asking for clarifications that the festival had cost VND94 trillion ($4.82 billion), or one tenth of the country's gross domestic product.
Officials had said then that the event's expenditure shouldn't include investments in buildings and infrastructure that marked the event, as they would still have been built even without the celebration.
The figures had not been released until now as officials said it includes money from the federal and city budget, as well as sponsorship from businesses, groups and individuals, they said.
It was revealed at Wednesday's meeting that the city spent 14.9 percent more of its budget than planned early this year.
The extra money was spent on the anniversary, social security, education facilities and improving infrastructure in rural areas, officials said.