01 · Overview
Two competitions, one mission
The International Chemistry Olympiad (IChO) and the International Biology Olympiad (IBO) sit at the pinnacle of pre-university science competition. Both run annually, rotating between host countries. Around 80 nations send teams of up to four students who compete across two days of written theory and one day of practical laboratory work.
IChO
- Founded 1968 (Prague)
- ~80 countries, ~300 competitors
- 5-hour theory paper (8 problems)
- 5-hour practical (3 tasks)
- Syllabus: analytical, inorganic, organic, physical chemistry
IBO
- Founded 1990 (Olomouc)
- ~70 countries, ~280 competitors
- 3-hour theory (multiple choice + open)
- 3-hour practical (microscopy, biochem, dissection)
- Syllabus: cell biology, genetics, ecology, physiology
Both competitions test understanding far beyond school level. The IChO Preparatory Problems — released by each host country in the preceding year — are the most reliable guide to the expected depth. For IBO, the official syllabus document and past practical descriptions define the lab skills you need.
02 · Qualification
How to make the team
Qualification routes differ by country, but the pattern is the same everywhere: national rounds → training camp → team selection.
School / regional round
Open to all eligible students. Usually a written paper sat in school.
National round
Top scorers from round 1. Harder questions, sometimes a practical component.
Training camp
~10–20 students attend intensive workshops led by university academics.
Team of 4 selected
Performance at camp determines who represents the country internationally.
In the UK, the Chemistry Olympiad is run by the Royal Society of Chemistry. The US Biology Olympiad (USABO) is administered by the Center for Excellence in Education. Check your national science society's website for entry dates — most open in September or October for an event the following spring.
03 · Preparation
Building the knowledge you need
For IChO
The gap between school chemistry and IChO level is significant. Start by securing a deep understanding of:
- Moles and stoichiometry — every quantitative problem builds on this. See the Moles guide and the Molar mass entry.
- Electrochemistry — half-cells, Nernst equation, and electrolysis feature in most IChO theory papers. Electrochemistry guide →
- Reaction kinetics — rate laws, activation energy, and the Arrhenius equation. See Activation energy and the Reaction rates guide.
- Acids, bases, and equilibrium — buffer calculations, Ka/Kb, solubility products. Acids and bases guide →
- Spectroscopy — IR, NMR, and mass spectrometry are tested at IChO but rarely at school level. University-level organic chemistry textbooks are the best resource here.
For IBO
IBO expects comprehensive knowledge across all of biology. Key areas where students gain or lose the most marks:
- Genetics and inheritance — Mendelian ratios, linkage, chi-squared, and molecular genetics. Genetics guide →
- Cell biology and biochemistry — membrane transport, enzyme kinetics (Michaelis–Menten), and cell signalling. Cells and organelles →
- Evolution and systematics — phylogenetics, Hardy–Weinberg, and speciation mechanisms. Evolution guide →
- Lab skills — practice using a haemocytometer, interpret electrophoresis gels, and understand basic dissection technique before arriving.
The single most effective resource is past papers. Work through IChO or IBO problems with solutions, identify gaps, and revisit the underlying science until each step feels natural.
04 · Recognition
What winning — and competing — means
Medals are awarded on a relative scale: gold to the top 10 % of competitors, silver to the next 20 %, bronze to the next 30 %. Roughly 60 % of competitors receive a medal of some kind. A special prize is sometimes given for the highest practical score.
Beyond medals, the Olympiad experience signals strong independent research ability to university admissions tutors and, later, to graduate programmes. Many IChO and IBO medalists go on to win national fellowships, Rhodes Scholarships, and Nobel Prizes — not because the medal predicts the prize, but because both reflect the same deep curiosity.
Even reaching the national final is worth including on university applications. Selectors at research universities understand what it means to progress through rounds run by national scientific societies.
International Science Olympiad — common questions
- Each country selects its own team of up to four pre-university students (under 20 at the time of the competition). Students compete in national selection rounds — such as the UK Chemistry Olympiad or USABO for biology — before being considered for the international team.
- The term covers a family of subject-specific competitions. The International Chemistry Olympiad (IChO) and the International Biology Olympiad (IBO) are the two most prominent, each governed separately. There are also olympiads for physics, mathematics, astronomy, and more.
- IChO problems span analytical, inorganic, organic, and physical chemistry. Core areas include moles and stoichiometry, equilibrium, thermodynamics, electrochemistry, spectroscopy, and reaction mechanisms. The Preparatory Problems released by each host country are the best guide to the difficulty and style of a given year.
- IBO covers cell biology, genetics and evolution, plant anatomy, animal physiology, ethology, biosystematics, and ecology. Practical skills — microscopy, gel electrophoresis, and dissection — are tested in the lab component. Past papers are available on the official IBO site.
- Gold medals go to the top 10 % of competitors, silver to the next 20 %, and bronze to the next 30 %. A special prize is sometimes awarded for the best experimental performance. All participants receive a certificate of participation.