Scaling is a process of standardizing marks (the mean, highest and lowest marks) so that marks can be compared across different subjects. Without scaling, it would be impossible to know whether a 90 in a subject like 4 Unit Maths is better than a 90 in a subject like 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? First, we must convert all their currencies into a single Australian Dollar, so that they can be compared. In much the same way, the Universities Admission Centres converts all HSC scores into a universal UAC score, so that marks in different subjects can be compared.

It is important to know about scaling because it has a very large impact on your ATAR. It is important to know about scaling so that you can get a measure of how you marks in different subjects will ultimately contribute to your overall ATAR. For instance, when doing a very highly scaled subjects such as 4 Unit Maths, you only need to be average in order to achieve a mark that is comparable to a very top mark (Top 2%) in a subject such as legal studies.

In fact, understanding scaling properly can help you organise your studies in a very efficient and results-focused manner. Study smarter, not harder

Suppose you are going to a fairly decent school and are coming 10th in 4 Unit Maths, and 25th in a subject like Advanced English. Furthermore, let's assume that you have a limited time to study, and that if you invested all your time in 4 Unit Maths, you know you could come 1st, whilst alternatively, if you invested all your time in English you believe you could only come 15th. Where should you invest your time?

Your intuition might tell you to invest all your time in Mathematics, 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 are only likely to see a very small increase in your ATAR. In contrast, improving 10 ranks in a lower scaling subject such as English will improve your scaled mark much more than it will in 4 Unit Maths. This is 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.

In fact, you can use an understanding of scaling to 'translate' any ATAR goal into ranks in each of your particular subjects. You can use our ATAR Calculator or our 'HSC Study Guide' to show you exactly what you need in each of your subjects to target any ATAR.

The highest scaling subjects are

1. 4 Unit and 3 Unit Mathematics
2. Physics, Chemistry
3. English
4. Economics

The scaling for 3 and 4 Units 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.

Finally, the humanities do not generally score as well as Maths, Physics and Chemistry and Advanced English.

Economics and Modern History scale much better than Legal Studies, Commerce, and Business Studies.

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 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 is very important in determining 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 if you are capable so that you can do pursue your professional interests later in your life.

If you would like to learn more about scaling, please refer to the scaling article in our 'HSC Study Guide'.

For a more in depth and personalised analysis, Talent 100 regularly provides Scaling Seminars in both our branches, which are completely free to join. Email us now to book your place.