Scaling is a process of standardising marks so that they can be compared across different subjects. Without scaling, it would be impossible to know whether a 90 in 4 Unit Maths is better than a 90 in Legal Studies.

In laymen's terms, scaling marks is like converting them into a 'Universal Currency' so that marks in different subjects can be compared. To draw an analogy, when tourists from the US, China and Europe come to Australia, how do we know how much their money is worth? We must convert all their currencies into a single Australian Dollar. In the same way, the Universities Admission Centre converts all HSC scores into a universal UAC score, so that marks in different subjects can be compared.

It is important to understand scaling so you can get a measure of how your marks in different subjects will contribute to your overall ATAR. Understanding scaling helps you organise your studies in an efficient and results-focused manner. Study smarter, not harder!

Suppose you are in an average school, coming 10th in 4 Unit Maths and 25th in Adv. English. Furthermore, let's assume that if you invested all your time in 4 Unit Maths, you could come 1st, whilst if you invested all your time in English you could only come 15th. Where should you invest your time?

Your intuition might tell you to invest your time in 4 Unit Maths, as you will be topping the highest scaling subject. However, what scaling actually tells you is that you should invest your time in English. The reason is that the scaling for 4 Unit Maths is so high, that whether you finish 10th or 1st, you will only see a small increase in your ATAR. In contrast, improving 10 ranks in a lower scaling subject (English) will improve your scaled mark much more because in a relatively lower scaling subject, you need a relatively higher rank in order to score an equivalent mark.

The above example is a simplification, but demonstrates how you can use your understanding of scaling to organise your studies in the most ATAR efficient way. You can use our ATAR Calculator or our HSC Study Guide to show you exactly what you need in each of your subjects to achieve any ATAR.

The highest scaling subjects are -

The scaling for 3 and 4 Unit Mathematics is significantly higher than the other subjects. Physics and Chemistry do not scale as well as Mathematics, but scale much higher than the other sciences (Biology and Earth and Environmental science) and certainly the other humanities. Advanced English scales in rough parity with Physics and Chemistry, and much higher than Standard English. Standard English is to be avoided where possible.

There are no 'right' or 'wrong' subjects, only subjects that scale higher and subjects that scale lower. There's nothing wrong with taking low-scaling subjects. What this means though is that you will need to score relatively higher positions in those subjects than you would in high- scaling subjects.

Generally, if you are looking for the highest ATAR you should take the highest scaling subjects if you are certain you can score reasonable marks. This last part is very important. No amount of scaling can help you if you are failing your subjects.

As with many other things in life, you need to weigh up the costs and benefits of your own decisions. Your ATAR will determine the course you study at University, and therefore the early part of your career. Thus, even if you enjoy the lower scaling subjects, it might be advisable to opt for the higher scaling subjects so that you can pursue your dream career later in your life.