Cambridge IGCSE Chemistry (0620) grade boundaries tell you exactly how many raw marks separate you from each grade. Understanding them helps you set precise revision targets rather than chasing vague percentage goals.

IGCSE Chemistry Paper Structure and Total Marks

Cambridge IGCSE Chemistry (0620) combines multiple papers for a total of 200 marks:

• Paper 1: Multiple choice (40 marks)
• Paper 2 (Core) or Paper 3 (Extended): Structured questions (80 marks)
• Paper 5 or Paper 6: Practical or Alternative to Practical (40 marks)

Extended candidates take Papers 1, 3 and 5/6. The grade boundaries below apply to Extended entry (grades A*–E).

Historical IGCSE Chemistry Grade Boundaries (Cambridge 0620)

Year	A*	A	B	C	D	E	Total
2024	165	137	109	81	55	38	200
2023	162	134	107	79	54	37	200
2022	163	135	107	80	54	38	200
2021	160	132	105	78	53	37	200
2019	158	130	103	77	52	36	200

Approximate averages from Cambridge published grade threshold documents (May/June series). Verify against official Cambridge documents.

Why Boundaries Vary Year to Year

Chemistry boundaries fluctuate by ±8–12 marks between years. The key driver is paper difficulty. If Paper 3 contains harder stoichiometry or organic chemistry questions than usual, the A* boundary drops — Cambridge compensates so that students of the same ability get the same grade regardless of which year’s paper they sat.

This is why targeting “80% = A*” is unreliable. The actual A* boundary has ranged from approximately 79% to 83% (158–165 marks out of 200) across recent years.

Practical Revision Targets Based on Historical Data

Based on 2019–2024 averages:

• A:* aim for 163+ marks out of 200
• A: aim for 134+ marks out of 200
• B: aim for 107+ marks out of 200
• C: aim for 79+ marks out of 200

These targets give you a buffer against years when boundaries are slightly higher than average.

High-Value Topics in IGCSE Chemistry

Paper 1 (Multiple Choice — 40 marks):

• Atomic structure and bonding (2–3 questions every year)
• Moles and stoichiometry calculations
• Electrolysis products
• Organic chemistry functional groups

Paper 3 (Extended Structured — 80 marks):

• Stoichiometry calculations (moles, concentration, titration) — always 8–12 marks
• Rates of reaction (particle theory, activation energy)
• Acids, bases and salts (neutralisation, salt preparation)
• Electrochemistry (electrolysis, electrode products, half equations)
• Organic chemistry (alkanes, alkenes, alcohols, reactions)
• Haber process and Contact process (conditions and reasoning)

Paper 5/6 (Practical — 40 marks):

• Designing fair tests and identifying variables
• Interpreting graphs (gradient, anomalies, extrapolation)
• Titration technique and calculation

Where Chemistry Students Most Commonly Lose Marks

The biggest mark-loser in IGCSE Chemistry is particle-level imprecision. Mark schemes require specific terminology:

❌ “Particles can move and carry electricity” — 0 marks ✅ “Ions are free to move and carry charge” — mark awarded

❌ “The reaction gets faster” — too vague ✅ “The frequency of successful collisions per second increases because more particles have energy equal to or greater than the activation energy” — full marks

The Mark Scheme Decoder for IGCSE Chemistry helps you practise writing answers with exactly the right precision — with instant auto-marked feedback.

Tracking Your Position Against Grade Boundaries

Enter your practice marks into the Grade Boundary Tracker to see instantly which grade band your current scores fall into for Chemistry, and how many marks you need to reach the next grade.

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