Its figures show that a typical pensioner spends £10,020 a year on essentials such as housing, heating, food and drink.
They also reveal that pensioners spent a total of £103.9billion on basic living costs last year, with more than £16.4billion of that going on housing and energy bills.
Dean Mirfin of Key Retirement Solutions told the Daily Mail: "The basic cost of living for a pensioner covers only the basics, without much scope for emergency spending or any luxuries. The state pension is a vital safety net, but cannot deliver all the income needed."
Not all pensioners are in the same boat, though. Where they live in the country has a massive impact on the amount they require to cover basic living costs.
Those living in London, for example, spend close to £12,300 a year on day-to-day essentials, while those living in the Welsh capital Cardiff can get by on just £8,180.
"It is clear that where you live matters very much in how expensive your life in retirement will be," Murfin added. "The £4,100 gap between Cardiff and London is a major difference."
The study indicates that, as might be expected, London is far and away the most expensive British city for pensioners to live in.
However, other cities where life is expensive for older people include Belfast, where the annual cost of maintaining a basic standard of living is £9,929, and Bristol, where the average pensioner spends £9,862 a year.
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At the other end of the scale, older Britons living in Hull spend just £8,596 on the same items, while those in Newcastle have an annual bill of £8,221.
And while Londoners might argue that the benefits of living in the English capital make the extra cost worth paying, the website Whycardiff.com - which is aimed at people considering a move to the Welsh capital - begs to differ.
"Cardiff offers all of the features and benefits of a capital city, at a low cost," it said.
Most expensive cities for pensioners
1. London - £12,300
2. Belfast - £9,929
3. Bristol - £9,862
Cheapest cities for pensioners
1. Cardiff - £8,180
2. Newcastle - £8,596
3. Hull - £8,596
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