International Science Olympiad (formerly NSO) 2026-27
NSO (now ISO) is the science olympiad that SOF (Science Olympiad Foundation) runs for Classes 1 to 12. Children who do well in Level 1 go on to Level 2 (Classes 3 to 12).
When is NSO (now ISO) 2026-27?
30 Oct 202619 Nov 20263 Dec 2026
On paper, in their own school during school hours. The school picks one of the dates.
How do I register my child, and what does it cost?
Through the school only (no individual registration). If your school doesn't run it, it can sign up free. Last date: usually 30 days before the exam date. Fee: ₹170. School may add up to ₹30. Outside India: US$11. It is free for children with a major physical disability, and for a child of a soldier martyred in defence operations.
What is in the paper?
Classes 1 to 4: 35 questions, 40 marks. Class 5 up: 50 questions, 60 marks (questions in Achievers, the hardest section, carry 2 to 3 marks each). It takes 60 minutes. Sections: Classes 1 to 10: Logical Reasoning, Science, Achievers. Classes 11 and 12: Physics & Chemistry, Achievers, Maths/Biology. Negative marking: not published. Language: English.
What is the syllabus?
CBSE, ICSE/ISC and state boards. Split: 60% current, 40% previous (Achievers, the hardest section, is from the current class only).
The topics, class by class, as the organiser lists them:
Class 1
Section – 1 : Patterns, Odd One Out, Measuring Units, Geometrical Shapes, Spatial Understanding, Grouping of Figures, Analogy, Ranking Test, Problems based on Figures. · Section – 2 : Living and Non-living Things, Plants, Animals, Human Beings and Their Needs, Good Habits and Safety Rules, Air and Water, Weather and The Sky. · Section – 3 : Higher Order Thinking Questions - Syllabus as per Section – 2.
Class 2
Section – 1 : Patterns, Odd One Out, Measuring Units, Geometrical Shapes, Analogy, Ranking Test, Grouping of Figures, Embedded Figures, Coding-Decoding. · Section – 2 : Plants, Animals, Human Body, Food, Housing and Clothing, Family and Festivals, Good Habits and Safety Rules, Transport and Communication, Air, Water and Rocks, Earth and Universe. · Section – 3 : Higher Order Thinking Questions - Syllabus as per Section – 2.
Class 3
Section – 1 : Patterns, Analogy and Classification, Alphabet Test, Coding-Decoding, Ranking Test, Grouping of Figures and Figure Matrix, Mirror Images, Geometrical Shapes, Embedded Figures, Possible Combinations, Clock and Calendar. · Section – 2 : Plants and Animals, Birds, Food, Housing, Clothing and Occupation, Transport, Communication and Safety Rules, Human Body, Earth and Universe, Matter and Materials, Light, Sound and Force, Our Environment. · Section – 3 : Higher Order Thinking Questions - Syllabus as per Section – 2.
Class 4
Section – 1 : Patterns, Alphabet Test, Coding-Decoding, Ranking Test, Mirror Images, Geometrical Shapes and Solids, Embedded Figures, Direction Sense Test, Possible Combinations, Analogy and Classification, Clock and Calendar. · Section – 2 : Plants, Animals, Food and Digestion, Human Needs, Matter and Materials, Force, Work and Energy, Our Environment, Earth and Universe. · Section – 3 : Higher Order Thinking Questions - Syllabus as per Section – 2.
Class 5
Section – 1 : Patterns, Analogy and Classification, Geometrical Shapes, Mirror and Water Images, Direction Sense Test, Ranking Test, Alphabet Test, Logical Sequence of Words, Puzzle Test, Coding-Decoding, Clock and Calendar. · Section – 2 : Animals, Human Body and Health, Plants, Natural Resources and Indian Heritage, Pollution and Calamities, Earth and Universe, Matter and Materials, Force and Energy. · Section – 3 : Higher Order Thinking Questions - Syllabus as per Section – 2.
Class 6
Section – 1 : Verbal and Non-Verbal Reasoning. · Section – 2 : The Wonderful World of Science, Food and Its Components, Materials Around Us, A Journey through States of Water, Methods of Separation, The Living World and Its Diversity, Exploring Magnets, Measurement of Length and Motion, Temperature and Its Measurement, Beyond Earth, Natural Resources. · Section – 3 : Higher Order Thinking Questions - Syllabus as per Section – 2.
Class 7
Section – 1 : Verbal and Non-Verbal Reasoning. · Section – 2 : The Ever-Evolving World of Science, Life Processes in Plants, Life Processes in Animals, Acidic, Basic and Neutral Substances, The World of Metals and Non-metals, Adolescence : A Stage of Growth and Change, Heat Transfer in Nature, Changes Around Us - Physical and Chemical, Measurement of Time and Motion, Electricity: Circuits and their Components, Light : Shadows and Reflections, Earth, Moon and the Sun. · Section – 3 : Higher Order Thinking Questions - Syllabus as per Section – 2.
Class 8
Section – 1 : Verbal and Non-Verbal Reasoning. · Section – 2 : Exploring the Investigative World of Science, The Invisible Living World : Beyond Our Naked Eyes, Health : The Ultimate Treasure, Particulate Nature of Matter, Elements, Compounds and Mixtures, How Nature Works in Harmony, Exploring Forces, Solute, Solvent and Solutions, Electricity : Magnetic and Heating Effects, Light : Mirrors and Lenses, Our Home : Earth, a Unique Life Sustaining Planet, Pressure, Winds, Storms and Cyclones, Keeping Time with the Skies. · Section – 3 : Higher Order Thinking Questions - Syllabus as per Section – 2.
Syllabus topics and a sample question for your child's class:
Is there a Level 2, and who goes?
Two levels (Level 2 for Classes 3 to 12).
Classes 3 to 12: the top 5% of each class worldwide, the top 25 of each class in each zone, and each school's class topper (when 10 or more children took the exam and the topper scored 50% or more). Classes 1 and 2 are ranked on Level 1 alone.
The Level 2 syllabus: on SOF's class syllabus pages.
Cut-off: Not published. Level 2 goes by rank, not a fixed mark.
How does my child get the admit card?
Roll number and admit card come through the school. If missing, the school asks SOF for a duplicate.
Is there an official NSO (now ISO) answer key?
Not published on SOF's own website.
When do results come, and what can my child win?
Within 8 weeks: sent to the school, and on SOF's results page.
- Every child: a certificate and a progress report
- Zonal top 25 per class: gold medal of distinction
- School gold medals
- Cash awards for international and zonal top ranks
Where can I find NSO (now ISO) sample papers and previous year papers?
One free sample paper per class to download on SOF's own website. Olympiad Owl does not share the papers themselves. Our class pages above have a free sample question each, and the app has full mock papers in the previous year paper pattern.
How can my child prepare for NSO (now ISO)?
A few questions a day in the real pattern, and one full timed paper a week, works better than a last-minute rush.
From SOF's own website · SOF's results page, 25 Oct 2026.
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