Australians pay far less tax than they believe, a new report finds, and certainly far less tax than the Treasurer thinks they do.

Mr Hockey told Fairfax radio on Monday that Australians paid nearly half their income in tax.

Mr 50 per cent: Joe Hockey says Australians spend six months of the year working to fill the government's coffers, a claim disputed by a new report. Credit:Christopher Pearce

"When Australians spend the first six months of the year working for the government with tax rates nearly 50 cents in the dollar it is a disincentive," he said.

"You're working July, August, September, October, November, December just for the government and then you start working for yourself and your own household income after that for another six months - it is a disincentive."