Does History Extension scale well? Yes, and better than almost every other humanities course in the HSC. In 2025, History Extension finished with a mean scaled mark of 32.7 out of 50, well clear of Modern History on 25.0 and Ancient History on 22.4, and roughly level with English Advanced (32.8) and Mathematics Advanced (31.9). For a one-unit course, that is a genuinely strong result.
But History Extension is scaled in an unusual way that almost no subject-selection guide explains, and understanding it changes how you should decide whether to take it. Here is the 2025 data and the mechanism behind it.
What was the History Extension scaled mean in 2025?
Table A3 of the UAC Report on the Scaling of the 2025 NSW HSC records the following for the three history courses, all reported per unit out of 50:
| Course | Students (2025) | Mean HSC mark | Mean scaled mark | Scaled SD |
|---|---|---|---|---|
| History Extension | 1,777 | 40.5 | 32.7 | 7.7 |
| Modern History | 10,953 | 37.1 | 25.0 | 11.1 |
| Ancient History | 7,495 | 36.4 | 22.4 | 11.0 |
History Extension scales 7.7 marks above Modern History and 10.3 above Ancient History. Note also the narrower standard deviation of 7.7 against roughly 11 for the two-unit courses. The Extension cohort is small and academically tight, so results cluster.
Why does History Extension scale so much higher than Modern History?
Because scaling does not measure the difficulty of the paper. It measures the overall academic strength of the students who take the course. History Extension is a self-selecting group: it is taken almost entirely by students already doing Modern or Ancient History who are confident enough to add a research-heavy fourth unit on top of a full pattern.
Those students tend to be strong across their whole HSC, so the course inherits a high scaled mean. It is the same effect that lifts every Extension course. For the underlying mechanics, see our guide on how to read the HSC scaling report.
How is History Extension actually scaled?
This is the detail that matters and that most guides skip. For most Extension courses, UAC works out the scaled mean from how those students performed in the matching two-unit course. History Extension is one of three named exceptions, because students can come to it from either Modern History or Ancient History.
UAC explains the method plainly: a scaled mean is determined for the Modern History students in History Extension based on their performance in two-unit Modern History, a scaled mean is found the same way for the Ancient History students, and the scaled mean for History Extension is then set equal to the weighted average of those two scaled means.
The practical consequence is significant. Your History Extension scaled mean is driven by how the Extension cohort performs in Modern and Ancient History, not by how anyone performs in the Extension paper itself. Doing well in your two-unit history course is therefore doing well for the Extension course too.
What does a good History Extension mark scale to?
UAC also publishes selected percentiles. For History Extension in 2025:
| Percentile in the course | HSC mark | Scaled mark |
|---|---|---|
| 99th | 48.0 | 47.0 |
| 90th | 47.0 | 42.7 |
| 75th | 45.0 | 38.1 |
| 50th (median) | 41.0 | 32.9 |
| 25th | 37.0 | 27.6 |
Two things stand out. First, the floor is high: even the 25th percentile of the course scaled to 27.6, which is above the mean for both Modern History and Ancient History. A weaker result in History Extension still contributes respectably to an ATAR aggregate. Second, the maximum recorded scaled mark was a full 50.0.
UAC is careful to warn that this is not a conversion chart. The report uses History Extension itself as its worked example: an HSC mark of 47.0 in History Extension corresponded to scaled marks at percentiles ranging from 87.2 to 96.2. The same HSC mark can sit on a range of raw marks and therefore a range of scaled marks.
Is History Extension worth taking as an eleventh or twelfth unit?
For a student already committed to Modern or Ancient History, usually yes. The ATAR counts your best two units of English plus your best eight units from everything else, so an extra unit gives you one more candidate for that top ten. A unit that scales to 32.7 on average has a real chance of displacing a weaker two-unit course from your aggregate.
An illustrative comparison. Take a student carrying English Advanced, Modern History, Ancient History, Business Studies and Legal Studies, which is 10 units. Business Studies scaled to a mean of 23.9 in 2025 and Legal Studies to 25.3. Adding History Extension as an eleventh unit means the weakest single unit in that pattern can be dropped from the aggregate. If the Extension unit lands anywhere near the course median of 32.9, it replaces a unit sitting closer to 24, a gain of roughly nine scaled marks in the aggregate. That is a meaningful ATAR movement for one extra unit.
The caveat is workload. History Extension is a major research project alongside a full HSC year, and the marks you sacrifice elsewhere are real. Our HSC subject workload guide sets out which courses already demand the most study time.
Do you need Modern History or Ancient History to take History Extension?
Yes. History Extension is built on the two-unit history courses, and NESA requires students to be studying Modern History, Ancient History or a related history course to enrol in it. That is also why UAC has to blend two scaled means to produce a single figure for the course.
If you are still choosing between the two-unit options, our comparison of Modern History against Ancient History scaling works through both courses in detail.
How does History Extension compare with other Extension courses?
Reasonably, though not at the top. On 2025 mean scaled marks: Mathematics Extension 2 at 43.4, Mathematics Extension 1 at 39.7, English Extension 1 at 36.1, English Extension 2 at 35.8, History Extension at 32.7 and Science Extension at 32.0.
The maths Extension courses sit clear of the field because their candidature is exceptionally strong across the board. Among the humanities and science Extension options, History Extension is competitive, and comfortably above every two-unit humanities course. Our ranking of the highest-scaling HSC subjects puts all of this on one list.
Can a low History Extension mark hurt your ATAR?
Rarely, and this is the safety net most students miss. Because the ATAR uses your best 10 units, a genuinely poor Extension unit simply falls out of the aggregate and the unit it would have displaced stays in. The realistic cost of History Extension is not the scaled mark; it is the study time it takes from your other subjects during Term 3 and Term 4.
Manage that by front-loading the research project. Students who finish the bulk of their Extension work before trials protect their other courses during the final run to the exams. Our guide to the 2026 HSC exam timetable shows how the written exam period is laid out from 13 October.
How should you decide before subject selection closes?
Ask three questions. Are you already strong in Modern or Ancient History, given that your Extension scaled mean is derived from performance in those courses? Do you enjoy independent research, because the course is built around a project rather than content coverage? And can you carry an eleventh or twelfth unit without your other five subjects slipping?
If the answer to all three is yes, History Extension is one of the better-value units in the HSC. If your two-unit history results are middling, the same hours are usually better spent lifting those.
Our tutors work with Modern, Ancient and Extension History students across NSW. If you want a considered view on whether the extra unit is right for your child’s pattern, book a first lesson today, or read how our HSC tutoring in Sydney programme is structured.
Frequently asked questions
Does History Extension scale well?
Yes. In 2025 History Extension had a mean scaled mark of 32.7 out of 50, compared with 25.0 for Modern History and 22.4 for Ancient History. It scaled at roughly the same level as English Advanced and Mathematics Advanced.
How is the History Extension scaled mean calculated?
UAC calculates a scaled mean for the Modern History students in History Extension based on their performance in two-unit Modern History, does the same for the Ancient History students, then sets the History Extension scaled mean to the weighted average of the two.
Is History Extension harder than Modern History?
It is different rather than simply harder. It is a one-unit course centred on a major independent research project and historiography, rather than syllabus content coverage. Its high scaled mean reflects the strength of the students who take it, not the difficulty of the paper.
Can History Extension lower my ATAR?
Not directly. The ATAR uses your best two units of English plus your best eight remaining units, so a weak Extension unit is dropped from the aggregate. The genuine risk is the study time it takes from your other courses.
Do I have to do Modern or Ancient History to take History Extension?
Yes. History Extension builds on the two-unit history courses, and the scaling method assumes students come to it from Modern History or Ancient History.