The International Monetary Fund says the Australian economy is now the 12th largest economy in the world, up from 14th a couple of years ago.
Radio New Zealand's Sydney correspondent says that's partly due to the economy outpacing much of the world and partly due to Europe is going backwards.
Australia's rise was at Spain's expense. Earlier, it leapfrogged Mexico and South Korea.
Meanwhile, another survey by Credit Suisse shows the median wealth of Australians is now the highest in the world. Median wealth per adult is now $US194,000, well ahead of Switzerland, Norway and Japan.
As well, the proportion of Australians with personal wealth above $100,000 is the highest of any country and eight times the world average.