Australia has been named the world's fourth most expensive country to live in by a study that also indicates China is poised to overtake the US as the world's biggest economy.

The International Comparison Program released data for its 2011 study in Washington overnight.

Paying the price: Australia is ranked behind Switzerland, Norway and Bermuda in the 2011 study. Credit:Virginia Star

According to the study, China's economy was 87 per cent of the size of that of the US in 2011, assessed according to so-called purchasing power parity (PPP).

The program, which involves organisations including the World Bank and United Nations, had put the figure at 43 per cent in 2005.