IAT exam pattern
A quick, student-friendly breakdown of the IISER Aptitude Test pattern using the 2026 official structure.
60 questions
15 questions each from Biology, Chemistry, Mathematics and Physics.
180 minutes
The 2026 IAT was a computer-based test with a 3-hour duration.
+4 / −1 / 0
4 marks for a correct answer, −1 for an incorrect answer and 0 for unanswered.
240 maximum
The maximum possible score under the 2026 marking scheme was 240.
Simple strategy
Because every subject contributes 15 questions, ignoring one subject creates a real ceiling on your score. Use the calculator to test different correct/wrong combinations before mock tests.
Reference cycle: IAT 2026. Rules, question counts or marking may change in a future cycle, so always verify the current official brochure.