A fraction of those asked said they would sell their home to raise money
The average person's savings would last for 52 days if they found themselves out of work, a report by the Yorkshire Building Society has suggested.
Monthly outgoings hit £1,445 for the average person in the UK but they only had £2,474 in accessible savings.
A survey of 2,000 people found a fifth did not know how they would manage if they lost their job, another fifth said state benefits would be enough.
A debt charity says that advice is available for those in trouble.
The survey found that 36% of people asked would run out of money within 11 days if they found themselves jobless because they had savings of less than £500.
Those who are divorced faced the biggest cash problems if they lost their jobs, the study found, followed by part-time workers and young people.
About 5% of respondents said they would sell their homes to get access to cash.
"Finances for many are already finely balanced due to the rising cost of living and the research reveals that both state benefits and savings are not viable options for the majority of consumers to rely upon for an adequate length of time," said Tanya Jackson, corporate affairs manager at Yorkshire Building Society.
But debt advice charity, the Money Advice Trust, said consumers facing difficulty could seek free advice.
They should prioritise bills, complete a budget sheet and call their mortgage lender immediately if they feared being unable to keep up with repayments.
"As the economy has deteriorated, many more people are living on the edge and a change in circumstances, as the report shows, could be devastating," said chief executive Joanna Elson.
"The good news is that there is free confidential, independent money advice available if people do get into difficulty."