IGCSE Chemistry grade thresholds explained 2026

IGCSE Chemistry grade thresholds are the minimum marks students need to achieve each grade in a specific Cambridge exam series. These boundaries are not fixed percentages; they change depending on paper difficulty and are calculated from the weighted marks across the relevant exam components. Understanding the difference between component and syllabus thresholds, as well as Core and Extended routes, helps students interpret their results more accurately.

This guide explains how Cambridge IGCSE Chemistry 0620 grade thresholds work and how to use them when reviewing past-paper performance.

What are grade thresholds in IGCSE Chemistry?

Grade thresholds are the minimum total marks a student must achieve to be awarded each grade in a Cambridge qualification. For IGCSE Chemistry (Syllabus 0620) ^[1], Cambridge publishes these figures after results are released for every exam series.

The thresholds cover grades A*, A, B, C, D, E, F, and G. A student whose total weighted mark falls below the G threshold is recorded as Ungraded (U).

One critical detail often overlooked is that thresholds are not fixed percentages. They are absolute mark values that shift depending on how difficult the papers were in that specific series.

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How Cambridge sets IGCSE Chemistry grade thresholds

Cambridge uses a process called grade awarding to set each session’s thresholds. Senior examiners review statistical performance data alongside sample student scripts to determine where each grade boundary should sit.

The goal is consistency of standard across years, not consistency of raw mark. If a paper was harder than usual, the A* boundary will be set lower to ensure the same level of performance is rewarded with the same grade.

This approach means Cambridge Chemistry grade thresholds are determined by expert judgment informed by data, not by a mechanical percentage calculation.

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Why IGCSE Chemistry grade thresholds change between exam series

A question we receive constantly at Times Edu is: Why did last year’s A* require 175 marks but this year only 169? The answer is paper difficulty and statistical calibration.

Each year, Cambridge writes new exam papers. Even with careful quality control, the difficulty level of individual questions varies. A paper with unusually complex calculation questions or unfamiliar contexts will produce lower average scores across all candidates.

To maintain a consistent standard, Cambridge sets a lower Chemistry 0620 grade threshold for harder papers and a higher threshold for more accessible ones. The grade you receive reflects your ability relative to the challenge of that specific paper, not an arbitrary fixed percentage.

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Component grade thresholds vs syllabus grade thresholds

This is one of the most misunderstood areas of IGCSE results. There are two distinct types of thresholds: Component grade thresholds and syllabus grade thresholds.

A component grade threshold refers to the minimum raw mark required on an individual paper (such as Paper 2, Paper 4, or Paper 6) to reach a particular grade band for that component alone.

A syllabus grade threshold is the minimum total weighted mark across all components combined that determines your final IGCSE grade. Your overall result is decided by the syllabus threshold, not by whether you hit each component threshold individually.

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How to read an IGCSE Chemistry grade threshold table

When Cambridge publishes its grade threshold document, you will see a table organized by syllabus code, entry option, and component. Reading it correctly is a skill that most students skip, to their own disadvantage.

Each row represents either a specific component or a complete component combination (entry option). The columns show the minimum marks required for each grade from A* down to G.

The row you care about most is the syllabus grade threshold row for your specific entry option, because that is the row that determines your final certificate grade.

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How Core and Extended grade thresholds differ

IGCSE Chemistry 0620 offers two routes: The Core route and the Extended route. Each route uses different papers and has a different grade ceiling.

Core route candidates sit Paper 1 (Multiple Choice Core) and Paper 3 (Core Theory), along with Paper 6 (Alternative to Practical) or Paper 5 (Practical). Core candidates can achieve a maximum grade of C.

Extended route candidates sit Paper 2 (Multiple Choice Extended) and Paper 4 (Extended Theory), along with Paper 6 or Paper 5. Only Extended candidates are eligible for grades A* through C. The grade thresholds for each route are published separately in the official Cambridge threshold document.

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How component combinations affect your Chemistry grade

Your component combination, also called your entry option, determines which set of syllabus grade thresholds applies to your results. Cambridge labels these options with codes such as CY or FK depending on whether you sit the practical paper or the alternative.

A common mistake we see is students comparing their total marks against the wrong entry option row in the threshold table. If you sat Paper 6 (Alternative to Practical), your total weighted mark must be compared against the threshold row for the option that includes Paper 6, not the one that includes Paper 5.

Always confirm your entry option with your school before attempting to self-calculate your grade from a threshold table.

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How weighted marks are used to calculate syllabus grades

For Extended route candidates in IGCSE Chemistry 0620, your raw paper marks are not added together directly. Cambridge applies a weighting factor to each component before combining them into a total weighted mark out of 200.

The weighting system reflects the relative importance of each paper:

Paper 4 carries the greatest weight at 50% of your final total, which has direct implications for how you should allocate revision time. A student who maximizes Paper 4 performance has the most leverage over their final grade.

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How many marks are needed for an A* in IGCSE Chemistry?

The A* grade boundary varies by exam series and variant. Drawing on years of experience at Times Edu helping students interpret their results, the following historical data provides a reliable planning baseline:

The data reveals a consistent pattern: June sessions demand higher total weighted marks for top grades compared to November sessions, and variant difficulty within the same June series can produce a six-mark difference in the A* threshold.

To give yourself a genuine buffer, target these raw mark benchmarks per component:

• Paper 2 (Multiple Choice): 34 to 36 out of 40 raw marks
• Paper 4 (Extended Theory): 55 to 60 out of 80 raw marks
• Paper 6 (Alternative to Practical): 30 to 33 out of 40 raw marks

Why there is no A* threshold for an individual component

One point that consistently surprises students is that A does not appear as a component-level grade. Cambridge does not award A on individual papers.

The A grade exists only at the syllabus level, meaning it is awarded based on your total weighted mark across all components combined. A student could perform exceptionally on Paper 4 and still not receive an A if their combined weighted total falls short of the A* syllabus threshold.

This also means that a poor performance on Paper 2 cannot be offset by an A on Paper 4 in isolation. Every component contributes to the total, and only the total triggers the A grade.

Can past grade thresholds predict future grade boundaries?

In our experience working with international students across multiple cohorts, past threshold data is genuinely useful as a planning tool, but it cannot be treated as a guarantee of future boundaries.

Cambridge thresholds for Chemistry 0620 have shown consistent general ranges over several years. The A* threshold for Extended route candidates in the June series has typically sat between 165 and 180 out of 200. Using the midpoint of that range as your personal target mark gives you a sensible and realistic revision goal.

Where past thresholds become misleading is when students treat a single year’s low boundary as a ceiling they only need to match. Chasing the lowest historical threshold is a high-risk strategy that leaves no safety margin.

How grade thresholds differ between March, June and November series

Cambridge IGCSE Chemistry 0620 is offered in three exam series: The March exam series (available in limited countries), the May/June exam series, and the October/November exam series.

Threshold data consistently shows that November sessions tend to have lower A* and A grade thresholds than June sessions. This likely reflects differences in the candidate population, paper variant difficulty, and overall performance distribution.

The March exam series has a much smaller candidature, and its threshold data is less representative as a benchmarking tool. Students sitting in March should use June data as their primary planning reference while acknowledging that their actual threshold may differ.

How to use grade thresholds when marking Chemistry past papers

One of the highest-value habits a serious IGCSE Chemistry student can build is integrating threshold data into their past paper practice. Here is a practical step-by-step approach:

1. Complete a full past paper under timed exam conditions.
2. Mark your answers using the official Cambridge mark scheme.
3. Record your raw mark for each component separately.
4. Apply the relevant weighting factor to calculate your weighted mark for each component.
5. Add the weighted marks to find your total out of 200.
6. Compare your total against the published threshold table for that specific series and variant.
7. Note which grade band you would have received and calculate the gap to the next boundary.

This process turns each past paper session into a data point that tells you exactly where you stand and which components need the most focused work. A student who scores 158 out of 200 in practice knows precisely that closing a 15-mark gap is the difference between a B and an A* in a typical November series.

Where to find official IGCSE Chemistry grade thresholds

The authoritative source for all Cambridge IGCSE Chemistry 0620 grade thresholds is the Cambridge International (CAIE) website. Cambridge publishes a grade threshold document for each exam series, typically at the same time as results are released.

To locate the correct document:

• Visit the Cambridge International website and navigate to the “Results” or “Grade Thresholds” section.
• Search for syllabus code 0620 along with the relevant series (for example, June 2025 or November 2025).
• Download the PDF threshold document and locate the rows for your specific entry option and component combination.

Be cautious about third-party websites that republish threshold data, as transcription errors are common. Always verify figures against the original Cambridge source.

Frequently asked questions

What are the grade thresholds for IGCSE Chemistry?

IGCSE Chemistry grade thresholds are the minimum total weighted marks a student must achieve for each grade from A to G. For Extended route candidates, these thresholds are calculated out of a total weighted mark of 200. Recent data shows the A threshold ranging from approximately 153 to 175 out of 200 depending on the series and variant.

How many marks do you need for an A* in IGCSE Chemistry?

For Extended route candidates sitting the May/June series, the A* threshold has typically fallen between 169 and 175 out of 200 in recent sessions. For the November series, the threshold has been lower, around 153 out of 200. These figures vary annually based on paper difficulty.

What percentage is an A* in IGCSE Chemistry?

Expressing the threshold as a percentage: 175 out of 200 equals 87.5%, and 169 out of 200 equals 84.5%. However, Cambridge does not use a fixed percentage for grade boundaries. The actual minimum mark shifts each session, so targeting 85 to 90% of the total weighted mark is a sensible planning heuristic rather than a guaranteed rule.

Do IGCSE Chemistry grade boundaries change every year?

Yes. Cambridge publishes new grade thresholds after every exam series. The boundaries move in response to paper difficulty and candidate performance. A harder paper produces a lower threshold; a more accessible paper produces a higher one.

Why do Cambridge grade thresholds change between exam series?

Cambridge adjusts thresholds to maintain a consistent standard of achievement across different years. The underlying question is always: Does this student demonstrate the same level of knowledge and skill as an A* student from previous years? If a paper made that demonstration harder to show, the threshold is adjusted downward to compensate.

Is there an A* grade threshold for each Chemistry paper?

No. Cambridge does not publish A thresholds at the component level. The A grade is awarded solely based on the total weighted syllabus mark. Individual component thresholds exist for grades A through G, but A* is a syllabus-only distinction.

Where can I find official Cambridge IGCSE Chemistry grade thresholds?

Official grade thresholds for Cambridge IGCSE Chemistry 0620 are published on the Cambridge International (CAIE) website. The documents are released alongside results for each exam series, typically in August for the June series and in January for the November series.

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