CSAT for UPSC Prelims 2027: How to Make Sure the Qualifying Paper Does Not Stop You

UPSC’s General Studies Paper II, commonly called CSAT, is qualifying: you need 33%, which is 66 marks out of 200, before your GS Paper I score is counted at all. For years many aspirants treated it as automatic. That has become risky. After Prelims 2026 on 24 May 2026, several post-exam analyses reported that many candidates found CSAT harder than GS Paper I, with long reading comprehension passages taking the most time.

The good news is that CSAT responds to practice more predictably than any other part of the exam.

The numbers you are working with

Feature	CSAT
Questions	80
Marks	200, so 2.5 marks a question
Time	2 hours, about 90 seconds a question
Negative marking	One-third of the marks for a question, about 0.83 marks per wrong answer
Qualifying mark	66 marks (33%)

To reach 66 marks you need 27 correct answers if you make no mistakes. Every wrong answer takes away a third of a correct one: 30 correct and 9 wrong gives 67.5, only just above the line. The margin is thinner than it looks.

Step 1: find your level this month

Take one past UPSC CSAT paper under exact conditions: two hours, no calculator, marked with negative marking. Then place yourself:

Your score out of 200	What to do
Above 120	A weekly full paper and one practice session a week will keep you safe
90 to 120	Practise three or four times a week, starting with your weakest area
Below 90	Practise daily for at least 45 minutes and take a full paper every week until you are consistently above 110

Step 2: comprehension

Reading comprehension makes up a large part of the paper and decides the result for many candidates.

• Read one or two passages daily from past papers
• Answer strictly from the passage. Options often include statements that are true in general but not supported by the passage
• Watch words like only, always, most likely and cannot, which change what a question asks
• For assumption and inference questions, choose what the author must believe or what necessarily follows, not what could follow
• Time yourself: a long passage and its questions should take no more than about three minutes

Step 3: basic numeracy

The mathematics is up to Class 10 level, but the questions test application. Build these areas in order:

1. Number system: divisibility, remainders, factors, HCF and LCM
2. Percentages, ratio and proportion, averages and mixtures
3. Profit and loss, simple and compound interest
4. Time and work, and time, speed and distance
5. Permutations, combinations and probability at a basic level
6. Data interpretation and data sufficiency

Keep a formula sheet for the first week, then practise without looking at it.

Step 4: reasoning and mental ability

Cover series, coding and decoding, directions, blood relations, seating arrangements, syllogisms, clocks and calendars, and puzzles. Many reasoning questions are faster to solve by testing the options than by working forwards, so practise both approaches.

Step 5: a plan for 80 questions in two hours

Three rounds protect you from spending too long on hard questions:

1. Round one, about 50 minutes: attempt every question you can solve in about a minute, whether comprehension, maths or reasoning
2. Round two, about 50 minutes: return to the longer passages and the maths questions that need working
3. Round three, about 20 minutes: attempt the rest only where you can eliminate options, and check your answer sheet

Decide your order by time per question, not by section.

A weekly CSAT routine

Day	Practice
Monday	Comprehension: four passages
Tuesday	Maths: one topic, 25 questions
Wednesday	Reasoning: one topic, 25 questions
Thursday	Comprehension: four passages
Friday	Maths and data interpretation: 25 questions
Saturday	A full CSAT paper under exam conditions
Sunday	Review the full paper and redo every wrong question

Scale this down if your diagnostic score is high.

Mistakes to avoid

• Assuming strong GS preparation will carry you through CSAT
• Practising only the areas you like
• Using a calculator during practice
• Starting CSAT practice in the last two months
• Trying to attempt every question on the paper

Frequently asked questions

What is the qualifying mark in UPSC CSAT?

33%, which is 66 marks out of 200. Your GS Paper I is counted for the Mains cut-off only if you reach it.

Is there negative marking in CSAT?

Yes. One-third of the marks for a question, about 0.83 marks, is deducted for each wrong answer.

How long should I prepare for CSAT?

It depends on your diagnostic score. If you score below 90 out of 200, practise daily for several months. If you score above 120, a weekly paper and some regular practice are enough.

Which is harder in CSAT, maths or comprehension?

It varies by candidate and by year. In 2026, many candidates said the long comprehension passages took the most time. Practise both, with extra time for your weaker area.