Australians are unable to account for a third of the cash they spend each week, despite more than 50 per cent of people trying to stick to a budget, a survey shows.

Australia has one of the highest proportional rates of cash spending which cannot be accounted for, a Visa survey shows.

More than a third of the $176 total cash spent per person per week, or $59 a week, cannot be accounted for, the survey of more than 1000 Australians conducted as part of a wider international survey of 12,000 adults found.

"The figure is more than double the international average in the survey which shows a cash spend of $120 per week with $24 not accounted for," Visa said in a statement.

Japanese and Americans were the best at keeping track of their money, with respondents in Japan losing track of only seven per cent of cash expenses and Americans failing to account for nine per cent of their weekly cash expenses.

The survey showed Australians cannot pinpoint where they spend $3,068 per year.

It also found 50 per cent of Australian women were most likely to lose track of their spending while shopping for food and groceries while 44 per cent of men were likely to lose track of spending during a night out or socialising.