For students completing the Western Australian Certificate of Education (WACE), scaling plays a critical role in determining final ATAR outcomes. While many students focus on their raw marks, it is ultimately their scaled scores that are used in ATAR calculations.
For students new to the system, it’s also useful to understand how ATAR calculations work overall, as scaled scores ultimately feed directly into your final ranking.
Despite its importance, scaling is often misunderstood. This guide provides a clear and detailed explanation of how WACE scaling works in 2025, what the latest data reveals about different subjects, and how students can use this information to make better academic decisions.
What Is WACE Scaling?
Scaling is the process used by the Tertiary Institutions Service Centre (TISC) to adjust raw subject marks so that results across different courses can be fairly compared.
Each WACE subject varies in difficulty, cohort strength, and assessment structure. Without scaling, students taking subjects with stronger cohorts or more rigorous marking standards could be disadvantaged. Scaling corrects for these differences.
In essence, scaling ensures that:
- A score in one subject can be meaningfully compared to a score in another
- Students are neither advantaged nor disadvantaged by their subject choices
- ATAR rankings reflect relative academic performance across the entire cohort
It is important to understand that scaling does not arbitrarily increase or decrease marks. Instead, it is based on statistical relationships between subjects and student performance across multiple courses.
💡For a broader overview of how WACE contributes to university pathways, students can also explore how the WACE system works and how subject results translate into ATAR outcomes.
How WACE Scaling Works
The process that leads to your final scaled score involves several stages.
1. Raw Score Calculation
Your raw score is derived from a combination of:
- School-based assessment (typically 50%)
- External WACE examination (typically 50%)
This produces a final mark out of 100 for each subject.
This guide breaks down how WACE scaling works in 2025, what the latest data tells us, and how to use scaling strategically when choosing subjects.
2. Moderation
Moderation ensures that results are comparable across different schools. Because schools vary in marking standards, student performance in the external exam is used to adjust internal school marks.
This step ensures fairness before scaling is applied.
3. Scaling (Standardisation)
Scaling adjusts subject scores based on:
- The overall ability of the cohort taking the subject
- How students in that subject perform in their other subjects
Subjects taken by academically strong students tend to scale upwards, while those with a broader ability range may scale down or remain neutral.
4. ATAR Calculation
Your ATAR is calculated using:
- Your best four scaled scores
- Plus up to 10% of a fifth and sixth subject
This means that even small differences in scaling can influence final rankings, particularly at the top end of the cohort.
💡Understanding this process is key, as even small differences in scaled scores can influence your final rank — particularly when aiming for competitive ATAR ranges. This becomes even more important when viewed alongside statewide ATAR benchmarks, which show how students are distributed across different score ranges.
WACE Scaling 2025: What the Data Shows
Using the latest TISC course statistics, we can identify clear patterns in how different subjects perform after scaling.
STEM Subjects Continue to Scale Strongly
Mathematics and science subjects consistently produce higher average scaled scores, indicating stronger scaling outcomes.
- Mathematics Specialist: mean scaled score of approximately 68.9
- Mathematics Methods: approximately 64.5
- Chemistry: approximately 63.2
- Physics: approximately 62.3
These subjects typically attract academically strong students, which contributes to higher scaling outcomes. However, this does not mean they are “easy ATAR boosters.” Students must still perform well relative to a strong cohort.
Languages Remain Among the Highest-Scaling Subjects
Language courses continue to demonstrate some of the highest average scaled scores:
- Chinese Second Language: approximately 70.0
- French Second Language: approximately 68.1
- Japanese Second Language: approximately 67.2
These subjects often have smaller, highly capable cohorts, which contributes to their strong scaling profile. However, they are also demanding, and strong performance requires sustained effort.
Humanities and Social Sciences Show Moderate Scaling
Subjects such as:
- Economics: approximately 59.5
- Modern History: approximately 57.7
- Geography: approximately 54.9
tend to scale in a more neutral range. In these subjects, your final ATAR contribution is driven more by your individual performance than by scaling effects.
High-Enrolment Subjects Tend to Scale Neutrally
Subjects with large student populations typically show minimal scaling adjustments. These include:
- English: approximately 57.3
- Mathematics Applications: approximately 55.3
- Human Biology: approximately 58.9
Because these subjects include a broad range of student abilities, their scaling reflects the overall average of the cohort.
Understanding Score Distributions
The dataset also provides insight into how scores are distributed across each subject.
For example, in Chemistry:
- Around 60% of students achieve a scaled score above 60
- Around 30% exceed 70
- Fewer than 10% exceed 80
This highlights two important points:
- High scores are relatively rare, even in strong subjects
- Competition becomes significantly more intense at higher score thresholds
This pattern is consistent across most ATAR subjects and explains why small improvements at the top end can have a significant impact on rankings.
💡This reinforces the importance of consistent performance across the year, rather than relying on last-minute improvement. Building consistent habits early — such as those discussed in scientifically proven study strategies— can make a significant difference over time.
Common Misconceptions About Scaling
“Hard subjects automatically boost your ATAR”
This is not necessarily true. While some subjects scale well, they also contain strong cohorts. A lower rank in a high-scaling subject can result in a weaker ATAR contribution than a high rank in a more neutral subject.
“Scaling will fix a low mark”
Scaling does not compensate for poor performance. It adjusts marks relative to other students, meaning your rank within the cohort remains the most important factor.
“Subject choice determines your ATAR”
Subject choice matters, but it is secondary to performance. A well-chosen subject is one in which you can consistently achieve strong results.
These misconceptions often lead students to over-prioritise subject difficulty instead of focusing on performance.
In reality, long-term success is more closely linked to strong study habits, as seen in the habits of highly successful students
Strategic Subject Selection for WACE 2025
When choosing subjects, students should adopt a balanced approach.
The most effective strategy is to select subjects that:
- Align with your academic strengths
- Maintain your motivation over two years
- Allow you to consistently achieve high marks
While scaling should be considered, it should not be the primary factor driving your decisions.
A student who scores highly in a moderately scaling subject will typically outperform a student who struggles in a highly scaling subject.
💡The most effective strategy is to select subjects that align with your strengths and allow for consistent performance. Creating a structured approach to your workload can also help — our guide on how to create a study plan that works outlines a simple way to stay on track.
Why WACE Scaling Matters
Scaling is designed to ensure fairness across the ATAR system. Without it, students would be incentivised to choose subjects based solely on perceived difficulty rather than genuine interest or ability.
In 2025, the data reinforces a consistent pattern:
- STEM and languages tend to scale more strongly
- High-enrolment subjects remain relatively stable
- Individual performance remains the dominant factor in ATAR outcomes
Students who understand how scaling works—and use it to inform, rather than dictate, their decisions—are best positioned to succeed. For those preparing for final assessments, reviewing the WACE exam timetable for 2025 can also help structure revision effectively.
Final Thoughts
WACE scaling is an important part of the ATAR system, but it is often overemphasised. The most reliable way to achieve a strong ATAR is not to chase scaling advantages, but to maximise your performance across all subjects.
Students who understand how scaling works—and use it to inform, rather than dictate, their decisions—are best positioned to succeed.
