Why Subject Choice Matters
Your Leaving Cert subject choices directly affect which CAO courses you can apply for. Many courses require specific subjects at a certain level (usually Higher Level). Choosing wisely in 3rd year ensures you keep options open for 5th and 6th year.
Compulsory Subjects
Most schools require (or strongly expect) the following core subjects:
- Irish — Required unless you have an exemption (available for students who did not attend primary school in Ireland, or with specific learning difficulties)
- English — Compulsory for nearly all courses and CAO points calculation
- Mathematics — Essential for most science, engineering, business and computing courses
- A modern language — French, German, Spanish or Italian (required for many arts, languages and humanities courses)
Points Scales by Level
Higher Level subjects offer the highest potential points. Here is how they compare:
- Higher Level: H1 (90–100%) = 100 points → H7 (30–39%) = 0 points
- Ordinary Level: O1 (90–100%) = 56 points → O7 (30–39%) = 0 points
- Foundation Level: Not counted for CAO points (used for establishing a minimum entry standard)
See our Points Calculator for the full breakdown.
Strategic Subject Selection
When choosing your optional subjects (usually 3–4), consider:
- Course prerequisites: Medicine requires Chemistry (usually HL). Engineering often requires Physics and/or Maths (HL). Nursing requires a science subject.
- Bonus points for Maths: Higher Level Mathematics gives bonus CAO points — 25 extra points for H6 or above.
- Your strengths: Taking subjects you enjoy and perform well in will maximise your points total.
- Balance: A mix of essay-based (English, History, Geography) and problem-based (Maths, Physics, Accounting) subjects spreads your workload.
Popular Subject Combinations
- Medicine: Biology, Chemistry, (Physics recommended), Maths, English, Irish, a language
- Engineering: Maths (HL), Physics, Design & Communication Graphics, Applied Maths
- Law: English, History, Irish, a language, any two others
- Business: Business, Economics, Accounting, Maths, English, a language
- Computer Science: Maths (HL), Physics, Computer Science (if available)
What If Your School Does Not Offer a Subject?
Some schools cannot offer every subject. Options include:
- Enrolling in a different school nearby (if spaces allow)
- Studying the subject independently (possible for some languages)
- Taking the subject through the Post Leaving Certificate (PLC) route later
- Using an online or community-based tuition programme
Changing Subjects
Most schools allow a change of subjects within the first few weeks of 5th year. After that, it becomes more difficult — so take your time choosing and ask subject teachers for advice before finalising.
New Subjects on the Menu (2025–2028)
Subject choice in 2026 is changing faster than ever. Two brand-new Leaving Cert subjects — Drama, Film and Theatre Studies, and Climate Action and Sustainable Development — began rolling out in schools from 2025 on a phased basis. In 2026, Tranche 2 of the senior cycle redevelopment became available in all schools: Construction Studies, Engineering, Geography, LCVP Link Modules and Physical Education, with English and Accounting delayed by at least a year. Tranche 3 arrives in 2027 (Agricultural Science, Computer Science, Design and Communications Graphics, History, Home Economics, Mathematics, Music, Physics, Chemistry) and Tranche 4 in 2028 (Art, Economics, French, Gaeilge, German, Italian, Politics and Society, Spanish, Technology).
The practical implication: students entering senior cycle now have a wider menu than any previous generation — but not every school offers every subject, so the availability in your school should drive your shortlist.
Subject Choice and the 2026 CAO Landscape
Your subject choices matter twice: they determine which college courses you can apply for, and they determine how many points you can realistically earn. The 2025 CAO points round shows how competitive the top courses have become — undergraduate medicine ranged from 728 points (University of Galway) to 739 (Trinity College Dublin), TCD Dental Science required 625, and UCD's Economics and Finance needed 625. For the first time ever, every UCD course required over 400 points in Round One 2025.
That means every subject you carry must be one you can score in. A strategic rule of thumb: take your strongest subjects at Higher Level (even if 'weaker' in prestige), meet the specific requirements of your target course (many science, engineering and business courses require specific subjects), and remember that Higher Level maths bonus points (25 for H6+) can be decisive.
The 2026 Cohort: Competition Is Fiercer Than Ever
Planning matters more in 2026 because the cohort is the largest ever: 71,698 Leaving Cert candidates, up 9% on 2025, with 146,553 students sitting State examinations overall. More candidates means more competition for the same number of CAO places — and the post-marking adjustment keeps results stable, so the points spread at the top of the distribution is the battleground.
If you are choosing subjects now, build a balanced set: two or three subjects you love, two you are strong at, and one 'insurance' subject you could carry if plans change. Avoid choosing a subject purely because a friend chose it, and avoid dropping a subject you enjoy just because it seems 'hard' — enthusiasm converts directly into marks at exam time.