IJSO 2027 exam dates
Each row links to the organiser's original notice.
- Nov2234 days leftRegister
No papers match these filters yet.Try clearing a filter, or check back soon - we're adding papers regularly.
About IJSO
The International Junior Science Olympiad (IJSO) is an annual international science competition for students who are 15 years old or younger on 31 December of the competition year. Each participating country sends a national team of up to six students, chosen through its own selection process, and the problems combine physics, chemistry and biology rather than testing each subject separately.
Because of the age rule, most IJSO competitors are in Grade 8-10, and for many of them it is a first international olympiad before the single-subject olympiads in physics, chemistry or biology. This page explains IJSO eligibility, the rounds, the IJSO exam format and scoring, and how to use IJSO past papers to prepare.
Overview
IJSO was first held in Jakarta, Indonesia, in 2004. It is run under written statutes by an international board of participating countries and an executive committee, and a different country hosts the competition each year. Recent hosts include Thailand (2023), Romania (2024) and Russia (2025), and Bulgaria is the announced host for 2026. According to the official website, around 50 member countries take part each year.
The stated aim is to challenge and encourage scientifically gifted young students. English is the working language: problems are approved in English and then translated by each country's team leaders into the students' own language, without hints or simplifications.
IJSO levels and grades
IJSO has a single level. Eligibility is set by age, not by school grade.
| Level | Grade | Notes |
|---|---|---|
| 15 and under | Grade 8-10 | Students must be 15 years old or younger on 31 December of the competition year. The grade range is approximate and depends on each country's school system. |
A student who turns 16 at any point during the competition year is no longer eligible, even if the olympiad itself is held before the birthday.
Rounds
IJSO has two stages. Only the second one is run by IJSO itself.
- National selection. Each country decides how to choose its team, so the format, dates and difficulty differ from country to country. In India, for example, the path starts with the National Standard Examination in Junior Science (NSEJS) and continues through further national stages. In Vietnam, the team has in recent years been selected by the Hanoi Department of Education and Training. Students cannot register for IJSO as individuals; they can only take part as members of an official national team.
- International olympiad. The selected teams travel to the host country for about a week. The competition itself consists of three tests held on different days.
IJSO exam format and scoring
The IJSO statutes describe three tests. Each normally lasts three to four hours, with at least one day between tests.
| Test | Type | Taken by | Maximum points |
|---|---|---|---|
| Test One | 30 multiple-choice questions (10 physics, 10 chemistry, 10 biology), four options with one correct answer | Individual | 30 |
| Test Two | Theory: two or three longer problems that combine physics, chemistry and biology | Individual | 30 |
| Test Three | Experimental: up to four practical tasks, in equal proportion across the three sciences | Team of three students | 40 |
Key scoring rules from the statutes:
- In the multiple-choice test, a correct answer earns 1 point, a wrong answer loses 0.25 points and a blank earns 0.
- In the experimental test, all three members of a team receive the same score. A full delegation of six forms two teams.
- Medals are based on each student's total of all three tests. Roughly the top 10% receive gold, the next 20% silver and the next 30% bronze, and medals must not exceed 60% of students.
These figures come from the published statutes. The rules can be amended by the international board, so check the current version on the IJSO website before relying on details.
When is it held
The international olympiad is held once a year in late November or early December, in a different country each time; the official website describes it as taking place in the first week of December. National selection usually takes place months earlier and its timing varies, so students should follow the announcements of the selecting body in their own country, usually through their school.
How to prepare with past papers
- Study the IJSO syllabus. The official website publishes a syllabus covering the three sciences. Use it as a checklist rather than relying on one country's textbook, since IJSO topics often go beyond a typical lower secondary course.
- Practise integrated thinking. Theory problems mix subjects in one context, for example energy in a biological system or the chemistry behind a physical measurement. Past papers show how these connections are built.
- Use the penalty wisely. With four options and a 0.25 penalty, a completely blind guess is worth very slightly more than a blank on average, and eliminating even one wrong option makes guessing clearly worthwhile. The bigger loss comes from careless errors, so read every stem carefully.
- Train for long papers. Three to four hours is a long time to stay focused. Do full papers in one sitting at least a few times.
- Do not skip lab work. The experimental test carries 40 of the 100 points and is done in teams. It cannot be practised on a screen, so school laboratory sessions and teamwork matter.
On Edupiad you can practise IJSO-style questions from past papers online with a timer, automatic marking and a question-by-question review afterwards. Coverage depends on which years have been added, and not every question has a worked solution. The experimental test cannot be practised online.
Frequently asked questions
What grade is IJSO for?
IJSO uses an age limit, not a grade: students must be 15 or younger on 31 December of the competition year. In most countries this means Grade 8-10.
Does IJSO have negative marking?
Yes, in the multiple-choice test. According to the IJSO statutes, a wrong answer loses 0.25 points, a correct answer earns 1 point and a blank earns 0. The theory and experimental tests have no such penalty.
How can a student take part in IJSO?
Only through a national team. Each country runs its own selection, so ask your school or the national olympiad organizer in your country. If your country does not participate, there is no individual entry route.
Is IJSO hard?
It is written for the strongest science students of each participating country. Questions combine three subjects and often require reasoning beyond the standard lower secondary curriculum, so most competitors prepare over a long period.
How is IJSO different from IPhO, IChO or IBO?
Those olympiads test one subject each and are for older secondary students. IJSO is for students aged 15 and under and combines physics, chemistry and biology in the same competition.