Wales' largest council says it faces a funding gap of up to £90m over the next three years.
But Cardiff council said it was as confident as it could be of making up the shortfall without hitting frontline services or compulsory job cuts.
After a request for voluntary redundancies, about 250 jobs are expected to go over the next year.
Councils are being hit by the double impact of falling budgets alongside rising service pressures.
Cardiff council leader Rodney Berman said: "I think we're looking over the next three years at having to plug a gap of about £90m - I think at the beginning of the year we were looking at about £56m.
"Things started to change when [former chancellor] Alistair Darling brought through his budget under the last government.
"We're now looking at about £30m to find in savings a year over the next three years."
He said the shortfall was mostly because of the expected reduction in funding from the assembly government.
Public finances are being squeezed, with the UK government announcing its Spending Review on 20 October.
"They've [the assembly government] told local councils to prepare for 3% year-on-year reductions in revenue funding and that's a large part of that £90m over the next three years," said Mr Berman.
He admitted that meeting this level of financial pressure would be challenging, and the council would have to reshape itself and its services.
But he said that redundancies would be voluntary.
"We're looking at ways we can make our services more efficient so we don't have to cut services so much," he said.
"That may be things like looking at our management structures - can we slim those down?
"We're looking at whether we can take out some of the administration that the council does. We're looking at things like can we get better value out of the way we purchase goods and services?
"We're also looking at can we deliver more services in collaboration with other nearby local authorities.
"If we take all those steps forward, we believe we can get to a position where we can get our budget to work."
When the council requested candidates for voluntary redundancy from its 18,000 employees, more than 1,000 people put their names forward.
The council expects to make around 250 of these redundant in the coming financial year.
Mr Berman also said he did not expect a dramatic rise in council tax.
He hoped to keep the increase at around the 3% figure which had been the average in recent years.
Steve Thomas, chief executive of the Welsh Local Government Association, said: "This is not unexpected, councils across Wales like Cardiff are all facing similar tough budget choices.
"We are pleased that Cardiff are seeking to avoid compulsory redundancies although we think the challenges ahead for both them and the other 21 authorities will be immense in the next period."