Sorry, don't know an exact answer as I have not tried to convert any Aus dollars. However in general the exchange rate you get at banks and currency exchange booths tends to be pretty in-line with the daily banking rate.
Changing at a hotel usually does not give the best rates.
One other thing is that unlike the UK and maybe Aus too, you are not charged a commission on exchanges - which can make quite a difference if you're changing a lot of money.
