Retirees tend to be a cautious bunch when it comes to their superannuation, but a new report warns that a growing number could exhaust their accounts before they die.

A new report based on studies by the Actuaries Institute and the CSIRO shows at least half of retirees conservatively draw down the regulated minimum of six per cent from their super accounts.

"Contrary to some views that retirees quickly run down their super balances and then rely wholly on the age pension, the reality is that at least half of the pensioners take a very financially conservative approach in retirement," the institute's Anthony Asher says.

This was regardless of the size of the accounts.

But the report predicts as the population ages, the number of retirees exhausting their super balances will grow because of those aged between 75 and 85, about a fifth of balances are being drawn down at more than 10 per cent, which is not sustainable for those who live longer than average.

This would put further pressure on both the federal budget and the aged pension.

Present regulation sets a minimum six per cent drawdown for those under 80 and minium seven per cent for those over.

The report found the average balance on death for retail and corporate super fund accounts was $50,000.

However, it points out this does not reflect a fully mature super system which reflects participation throughout a working life.