A complete guide to Cambridge IGCSE Combined Science

Cambridge IGCSE Combined Science is the international equivalent of GCSE Combined Science. The Cambridge family of qualifications has two routes here: Co-ordinated Sciences Double Award (0654), which earns two IGCSEs, and Combined Science (0653), which earns one. This guide focuses on the Co-ordinated Sciences route because it is by far the more common choice at international schools.

The qualification covers biology, chemistry, and physics in a single integrated course. It is fully linear, exam-only, and structured to be taught alongside more advanced subjects in a packed timetable. Here we walk through everything you need to know to sit the exam with confidence.

Co-ordinated Sciences is fully linear. All papers are sat at the end of the course, in either May/June or October/November. There is no coursework and no controlled assessment.

The qualification is tiered into Core and Extended. The Core route uses easier papers and gives access to grades C to G. The Extended route covers all of Core plus additional Extended-only content across all three sciences, and unlocks grades A* to E. Your school decides which route to enter you for based on mock performance.

Co-ordinated Sciences covers a substantial chunk of the single-subject Cambridge IGCSE specs (0610 Biology, 0620 Chemistry, 0625 Physics) but with reduced depth in some areas to fit three sciences into a single qualification.

Characteristics of living organisms, cells, movement in and out of cells, biological molecules, enzymes, plant nutrition, human nutrition, transport, gas exchange, respiration, excretion, coordination, reproduction, inheritance, variation, organisms and the environment, human influences, and biotechnology.

Particulate nature of matter, experimental techniques, atoms and elements, stoichiometry, electricity and chemistry, chemical energetics, rates and equilibrium, acids and bases, the periodic table, metals, air and water, and organic chemistry.

Motion, forces, energy, thermal physics, waves, light, sound, electricity and magnetism, electromagnetism, atomic physics, and space physics.

Co-ordinated Sciences has a 20% practical component. Schools can choose between Paper 5 (a physical practical test) or Paper 6 (a written alternative to practical paper). Both options test the same skills and are worth the same weighting.

A 2 hour practical exam sat in a lab. You will rotate through tasks covering biology, chemistry, and physics, recording observations, taking measurements, plotting graphs, and answering questions on method. It is marked out of 60.

A 1 hour written paper that tests the same practical skills as Paper 5 without any physical lab work. You answer questions on apparatus, methods, observations, and graph drawing using data provided in the paper.

Most international schools enter their candidates for Paper 6 because it is logistically much simpler than running a rotating lab exam. Both options assess the same skills and are worth the same weighting.

Co-ordinated Sciences is graded A* to G in each of the two IGCSE awards. The Core route gives access to grades C to G. The Extended route gives access to A* to E. There is overlap in the middle, so a strong Core candidate can earn a C and a weaker Extended candidate can earn an E or D.

Most academically strong students take Extended because it unlocks the higher grades and is widely accepted as equivalent to GCSE Combined Science Higher tier. Your school will normally make the route decision based on mocks.

Grade boundaries shift every series and are published by Cambridge on results day each August and January.

Co-ordinated Sciences covers three subjects in the time most students would normally give to one or two. The students who get A*/A* are not necessarily the strongest in any single science, but they are the most organised and consistent across all three.

Do not block-revise one science for two weeks and then move on. By the time you come back to it the content will have decayed. Rotate biology, chemistry, and physics across the week so that each gets touched at least twice.

Ion tests in chemistry and equations in physics are the two highest-yield pieces of pure recall in the whole spec. Make a single sheet for each, write it out daily, and quiz yourself on it weekly. These two sheets alone are worth a grade on Extended.

Cambridge mark schemes are strict about definitions. Diffusion, osmosis, active transport, transpiration, photosynthesis, respiration – memorise the textbook wording exactly. These definitions appear in nearly every biology section.

Graph questions appear on every paper, in every science. Practise plotting from raw data tables, drawing lines of best fit, and reading gradients and intercepts. Standardise your axis labels, scales, and units so it is automatic on the day.

With three sciences competing for your time, every past paper attempt has to earn its keep. Mark it honestly, write down every topic where you dropped marks across all three sciences, and revise that specific content before doing another paper.