Since 1 Euro is equal to 1.6459778871078663 Australian Dollars, we could say that n Euros are equal to 1.6459778871078663 times n Australian Dollars. In other words, we could use the following formula:
Australian Dollars = Euros x 1.6459778871078663
For example, let's say that we want to convert 2.0 Euros to Australian Dollars. Then, we just replace Euros in the abovementioned formula with 2.0:
Australian Dollars = 2.0 x 1.6459778871078663
That is, 2.0 Euros are equal to 3.2919557742157326 Australian Dollars.