There are three Credit Reporting Bodies (CRB) in Australia and each would have a different score for you because each calculate their own score using their own formulas and information available to them at that time.

There are several websites that can provide you with your credit score for free.  Each of these sites will provide you with a different score, depending on the CRB they refer to.  These are listed below.

It is a good idea to also obtain a copy of your credit reports so you can better understand some of the information which may have been used to calculate that credit score

See this FAQ on how to obtain a copy of credit file.