IGCSE Chemistry 0620 vs 4CH1: Cambridge vs Edexcel, explained for parents

Cambridge 0620: Core and Extended tiers · Extended sits 3 papers (multiple choice 30% · written 50% · practical 20%) · graded A* to G · Core can reach a C at most.

Cambridge 0971: the same content and papers as 0620, graded 9 to 1 instead.

Edexcel 4CH1: untiered, everyone sits the same 2 papers (61.1% + 38.9%), 180 marks in total · graded 9 to 1 · no practical exam; the set practicals are examined in the written papers.

Both run in June and November (Cambridge also has a March series in India only).

Switch boards below. The coloured bar is each paper's share of the marks; "min/mark" shows how pressed for time each paper is. Cambridge Paper 4 gives less than a minute per mark.

The 0620 syllabus says Core candidates (Papers 1, 3 and 5 or 6) are eligible for grades C to G, and Extended candidates (Papers 2, 4 and 5 or 6) for A* to G. If the aim is an A or A*, it has to be Extended.

The school makes the entry. Parents should check early in the year which tier their child is entered for, because Supplement content (including much of the mole calculations) is examined only on Extended papers.

The practical comes in two forms: Paper 5 is done in a lab, Paper 6 is a written alternative to practical. Both assess the same skills (AO3) and make up 20% of the grade.

Paper 1C is 2 hours and 110 marks, on content that is not in bold. Paper 2C is 1 hour 15 minutes and 70 marks, on all content including the deeper bold content. Both are taken in the same series and the marks are simply added, not scaled.

4CH1 has no separate practical exam. The practicals in the specification (such as chromatography or making copper(II) sulfate crystals) are examined through written questions, and experimental skills (AO3) are about 19–21% of the total.

June 2026 boundaries (Paper 1C + 2C, out of 180): grade 9 at 141 · grade 7 at 103 · grade 4 at 66. They move every series, as with Cambridge: in November 2025, grade 9 was 136.

The core chemistry is almost the same: states of matter, atomic structure and bonding, stoichiometry (the mole), acids, bases and salts, the Periodic Table, metals, rates and equilibrium, and organic chemistry. What differs is how topics are grouped, the depth of some of them, and the style of the questions.

So the real difference in preparation is the exam format, not the chemistry. Cambridge students need to practise Paper 6 separately; Edexcel students need to handle a 2-hour written paper with practical questions mixed in; and both need past papers and mark schemes from their own board.

Look at the code on past papers or the school's exam timetable: Cambridge looks like 0620/42 (the first digit after the slash is the paper, the second the variant); Edexcel looks like 4CH1/1C. If unsure, ask the chemistry teacher or the exams office which syllabus your child is entered for, and Core or Extended.

It matters when choosing a tutor too: one who does not know which board your child sits will teach from the wrong book or the wrong past papers.

The Boom-Tutor IGCSE Chemistry course covers the topics of both Cambridge 0620/0971 and Edexcel 4CH1, with interactives in every topic and practice in answering to the marking points. The self-learn course is ฿4,900, paid once. The platform is expected to open around December 2026.