Cambridge IGCSE Computer Science 0478: papers, topics, dates and grades

IGCSE Computer Science papers

Both papers are short-answer and structured questions, and all questions are compulsory. Paper 2 also has a scenario-based question where you write a longer program. When you write code, you can use pseudocode or one of Python, Visual Basic or Java; Cambridge says solutions in other languages get no marks. The syllabus sets out exactly how pseudocode appears in the exam, so learn that style. This is the 2026 to 2028 syllabus.

IGCSE Computer Science exam dates 2027

The June 2027 series runs from 26 April to 11 June 2027. Cambridge publishes a timetable for each zone, so check yours with your exams officer. November 2026 IGCSE results come out on 14 January 2027.

IGCSE Computer Science grade thresholds

Your two papers add up to 150. In June 2026, Cambridge set these thresholds:

The paper version you sit depends on your time zone, and thresholds change every series, so use these as a guide when you mark past papers.

What IGCSE Computer Science covers

Data storage uses binary prefixes: a kibibyte (KiB) is 1024 bytes and a mebibyte (MiB) is 1024 KiB.

Worked examples

Data representation: binary and hexadecimal

The 8-bit binary number 10110101 is 128 + 32 + 16 + 4 + 1 = 181 in denary. Split into nibbles, 1011 is B and 0101 is 5, so in hexadecimal it is B5.

Data representation: image file size

An 800 × 600 image with a colour depth of 24 bits needs 800 × 600 × 24 = 11,520,000 bits. Dividing by 8 gives 1,440,000 bytes, and dividing by 1024 gives 1406.25 KiB.

Boolean logic

For X = (A AND B) OR (NOT C), with A = 1, B = 0 and C = 0: A AND B is 0, NOT C is 1, and 0 OR 1 gives X = 1.

Programming: a running total in pseudocode

This reads 10 numbers and outputs their mean, using a count-controlled loop:

Total ← 0
FOR Count ← 1 TO 10
    INPUT Number
    Total ← Total + Number
NEXT Count
OUTPUT Total / 10

Practise converting binary to denary in our Number Systems course, then press Mark to check your answer in the course:

Use the daily paper as a short timed mock

Uni-Sine publishes a free daily paper for IGCSE Computer Science. Each is a short timed mock: 8 questions worth 25 to 35 marks, with a suggested 30 to 40 minutes, marked when you finish. It is not a full Cambridge paper, and the questions are original, not past papers.

• What it covers well: binary and hexadecimal, representing images and sound, the CPU and computer systems, networks and protocols, cyber security, data types and structures, algorithms and flowcharts, programming, searching and sorting, and Boolean logic.
• What it does not cover: the long scenario-based program in Paper 2, and automated and emerging technologies. Databases and SQL appear only occasionally.

For full papers under exam conditions, use Cambridge past papers from your teacher, and read our IGCSE mocks guide for when mocks happen and how to revise for them.

Common mistakes in IGCSE Computer Science

• Using 1000 instead of 1024. The syllabus uses KiB and MiB, which go up in 1024s.
• Writing code in an unlisted language. Only pseudocode, Python, Visual Basic or Java score.
• Skipping validation in the scenario question. Check inputs, and comment your code if it helps the examiner follow it.
• Vague definitions. Say what a term does and give a precise example, such as what a router actually forwards.

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