Irish Leaving Certificate

The Irish Leaving Certificate (Leaving Cert or LC) is the final examination of the Irish Secondary school system, administered by the State Examinations Commission (SEC). It is taken by students aged 16 to 19 after two years of study in the Senior Cycle.

Overview

The Leaving Certificate serves as the principal matriculation qualification for entry to higher Education institutions in Ireland, including universities, institutes of technology, and colleges of Education. It is also widely recognised internationally.

Levels

Each subject is offered at two levels:

• Higher Level (HL) — A more advanced and in-depth course, required for entry to competitive university programmes. Grades range from H1 to H8.
• Ordinary Level (OL) — A standard course suitable for students who may not intend to pursue the subject at third level. Grades range from O1 to O8.

The grading scale is as follows:

Percentage	HL Grade	OL Grade
90 — 100	H1	O1
80 — 89	H2	O2
70 — 79	H3	O3
60 — 69	H4	O4
50 — 59	H5	O5
40 — 49	H6	O6
30 — 39	H7	O7
0 — 29	H8	O8

Core Subjects

All students must study:

• Irish (except for exemptions)
• English
• Mathematics

Subjects Covered in These Notes

These notes provide comprehensive coverage for five Leaving Certificate subjects:

1. Mathematics — Algebra, calculus, geometry, trigonometry, probability, statistics, and number theory.
2. Physics — Mechanics, light and waves, electricity, modern physics, and heat and thermodynamics.
3. Chemistry — Atomic structure, bonding, stoichiometry, acids, bases, and organic chemistry.
4. Biology — Ecology, cell biology, human body systems, genetics and evolution, and plant biology.
5. Computer Science — Computer systems, data and databases, algorithms and programming, networking and security, and computational thinking.

Exam Structure

The Leaving Certificate examination is held annually in June. Each subject consists of one Or two written papers, each lasting between two and three hours. Some subjects also include Practical or project components that are assessed separately.

Calculating Points

For CAO (Central Applications Office) entry, Leaving Certificate results are converted to points. The highest six subjects are counted. Higher Level Mathematics attracts a bonus of 25 points for Grades H6 and above.

HL Grade	Points
H1	100
H2	88
H3	77
H4	66
H5	56
H6	46 (+25 bonus)

OL Grade	Points
O1	56
O2	46
O3	37
O4	28
O5	20
O6	12

Using These Notes

These notes are structured by subject and topic. Each topic covers material relevant to both Higher And Ordinary Level, with the level indicated. Worked examples, common pitfalls, and practice Questions are included throughout.

:::tip When studying, focus first on understanding the core concepts before attempting practice Questions. For Higher Level students, pay particular attention to the proofs and derivations, as These frequently appear on the examination. :::

State Examinations Commission (SEC)

The SEC is the statutory body responsible for the development, administration, and accreditation of The State examinations in Ireland. Its website at examinations.ie Provides past examination papers, marking schemes, and chief examiner reports — all invaluable Resources for revision.

:::info Past papers and marking schemes are available free of charge from the SEC website. Working Through past papers under timed conditions is one of the most effective preparation strategies. :::

Summary

The key principles covered in this topic are linked in the sub-pages above. Focus on understanding the definitions, applying the formulas or frameworks, and evaluating strengths and limitations of each approach.

Worked Examples

Worked examples demonstrating the application of key concepts are covered in the detailed sub-pages linked above.

Common Pitfalls

• Confusing terminology or concepts that appear similar but have distinct meanings.
• Overlooking key assumptions or boundary conditions that limit applicability.