Older people are "fearful of the future" and forced to "make do" in order to survive, according to a new report.
A study by Age UK shows that a third of its respondents are struggling just to buy basic supplies. The charity said that if this was projected nationally, it would equate to 4.5 million people aged over 60 who have to eke out their incomes.
Highlighting the "great resilience" of those on the breadline, its study Living on a Low Income in Later Life showed how people are forced to "make do", including going without basic household goods such as a television or an oven.
Living standards have been squeezed by the current low rate of returns on savings and rising household costs, particularly fuel bills.
The charity reported cases such as a 78-year-old woman living on £120 a week after rent who uses a hob and a microwave rather than replace a broken gas oven which she is concerned is leaking.
Other cost-saving examples found by researchers included boiling a kettle for washing rather than heating the water in a boiler, not replacing broken furniture and going without a television, the Press Association reported.
Age UK's study of more than 1,000 respondents found that nearly one in seven older people have gone to bed when they are not tired just to keep warm and around the same proportion said they live in just one room to save on heating.
Michelle Mitchell, charity director of Age UK said: "Living on a low income is hard work. Currently there are 1.8 million people in later life living in poverty but our polling suggests that many above the official poverty line are finding life hard.
"Older people tend to show a great deal of resilience in managing their money and eke out their income but this new report demonstrates exactly how emotionally draining it is for older people to constantly survive on a lower income and how many are fearful of the future in the current economic climate."
Nearly one in five of those surveyed said they would struggle to pay an unexpected bill of £150.
Highlighting gas and electricity cost worries among older people, the report said: "One participant commented that if things became worse, food was the only thing left to be cut down on."
The report noted that participants worked "incredibly hard" to manage their finances and most were "strongly averse" to debt, with some having built up a lifelong habit of staying in the black.
It found that older people were particularly concerned about rising prices and the possibility of losing benefits which enabled them to stretch their fixed incomes further.
Many participants often wrote their outgoings down and "planned every penny of spending with care", the report found, with a strong tendency among them to seek out the best bargain, for example by shopping later in the day to buy food which had been reduced in price.
The report found: "Older people on low incomes often have a very limited expectation of what is absolutely necessary - things that they will buy come what may.
"This means that they may potentially still have a bit to spare on those other things that they value most, whether it is getting their hair done, going out to the social club or enjoying a modest meal out."
The report also found older people were concerned about funeral costs, with one respondent even having bought her own coffin.
"This concern reflects older people's desire not to leave the responsibility to someone else, which they think would be unfair," it said.
The report was compiled for the charity by Loughborough University using 25 in-depth interviews as well as focus group discussions and Age UK also based its research on a survey of 1,003 adults.
A Department for Work and Pensions spokeswoman said the Government was involved with the Age Action Alliance, a partnership of voluntary and community groups working to improve older people's quality of life.
She added: "We want all pensioners to have a decent and secure income in retirement, and that is why we will spend around £45 billion more on the basic state pension by 2025."