An average stay in a residential home could swallow up as much as half of the value of your home, according to a study warning of a care-cost postcode lottery.
A typical stay of around 30 months in a residential home could equate to between 18% and 56% of the value of an average home, depending on where someone lives in the UK.
And the North East is the worst place in the country if a loved one needs care.
With the average house price in the region just under £129,000, people in the region could face an average care home cost equating to 56% of the cost of their home.
The typical weekly bill there would be £554 per week, bringing the cost of a 30-month stay to around £72,000, the analysis found.
By contrast, people living in London could find that 30 months in residential care equates to 18% of the value of their property.
The average house price in the capital is £484,000, and an average stay in a residential care home at £666 per week could cost around £86,600 in total.
And with care costs also varying across the country, someone entering residential care could typically face total bills of between £50,000 and £93,000, the research calculates.
Debbie Kennedy, head of protection at Royal London, which carried out the survey, said: "These figures are a shocking reminder of the huge costs which growing numbers of us will face if we need residential care later in life.
"Even an average stay in a care home can eat up half the value of your home, depending where you live in the country.
"The whole system is a lottery and we need to find better ways of supporting people to cope with these large and unpredictable bills".
Sir Steve Webb, a former pensions minister who is now director of policy at Royal London, said urgent action is needed to address care funding.
He said: "Successive governments have failed to grasp the nettle when it comes to care costs.
"For over 20 years we have had a series of Royal Commissions, expert reports and policy papers, but little has changed.
"With an ageing population, more and more of us will have loved ones needing long-term care, and we could see a large part of the value of our family home taken up in care costs."
The pensions company's analysis looked at residential care rather than nursing care.
It said the average stay in a nursing home tends to be significantly shorter than the typical stay in a residential care home, meaning the total bill for a nursing home is likely to be smaller.
In Scotland, someone could face a residential care home bill of around £50,000. Royal London said the figure is lower than it could otherwise be as the government in Scotland will meet certain costs, and its calculations reflect this.
Royal London used a range of data for its findings, including care home fee costs from healthcare researchers LaingBuisson and Office for National Statistics (ONS) house price figures.
Baroness Altmann, also a former pensions minister, said: "The care crisis is far worse than the pensions crisis."
She continued: "A range of solutions is needed, to help families prepare for care.
"Incentives to help people prepare for care costs should have been introduced long ago, but we are still waiting for action.
"Some people could use their pension savings, others their Isas, but many will have nothing other than the value of their homes."