UPSC Negative Marking Explained, With Worked Examples

In the UPSC prelims, every wrong answer costs you one-third of the marks that question carries. If you leave a question blank, you lose nothing. If you mark more than one answer, the question counts as wrong, even if one of your answers is right. The rule applies to both prelims papers and comes from the CSE 2026 notice; UPSC prints the same rule on the covers of its test booklets.

In CSE 2026, that meant a wrong answer cost two-thirds of a mark in General Studies Paper I and five-sixths of a mark in Paper II (CSAT). The worked examples below show what that does to a score.

The rule in the notice

The notice says every question has four alternatives, and that for each question answered wrongly, "one-third (0.33) of the marks assigned to that question will be deducted as penalty". It then adds two clarifications: giving more than one answer is treated as a wrong answer even if one of them is correct, and a question left blank carries no penalty.

The notice states the penalty as a share of each question's marks, not as a fixed number. For the actual figure you need the marks per question, which come from the test booklet.

What a wrong answer costs in each paper

UPSC's CSE 2026 test booklets give the number of questions and say all questions in a paper carry equal marks. Dividing the 200 marks of each paper by its questions gives the marks per question.

Paper (CSE 2026)	Questions	Marks per question	A wrong answer costs
General Studies Paper I	100	2 (200 ÷ 100)	Two-thirds of a mark
General Studies Paper II (CSAT)	80	2.5 (200 ÷ 80)	Five-sixths of a mark

In both papers, three wrong answers cost exactly what one right answer earns. The notice writes one-third as 0.33 but doesn't say how UPSC rounds fractions of a mark, so the examples here keep to fractions.

Worked examples

The answer counts below are made up to show the arithmetic. The marks per question are those of the CSE 2026 papers.

Example 1: General Studies Paper I

You answer 90 of the 100 questions: 60 right and 30 wrong, with 10 left blank.

• Right answers: 60 × 2 = 120 marks.
• Wrong answers: 30 × two-thirds = 20 marks deducted.
• Blanks: nothing added or deducted.
• Score: 120 − 20 = 100 out of 200.

Example 2: the same paper, fewer wrong answers

You get the same 60 right, but leave 15 of those 30 wrong answers blank instead: 15 wrong and 25 blank.

• Right answers: 120 marks.
• Wrong answers: 15 × two-thirds = 10 marks deducted.
• Score: 120 − 10 = 110. Fifteen fewer wrong answers are worth 10 marks.

Example 3: two answers marked

You mark two of the four answers for one General Studies Paper I question, and one of them is the correct answer. The notice treats this as a wrong answer, so instead of gaining 2 marks you lose two-thirds of a mark.

Example 4: CSAT

You answer 52 of the 80 questions: 40 right and 12 wrong.

• Right answers: 40 × 2.5 = 100 marks.
• Wrong answers: 12 × five-sixths = 10 marks deducted.
• Score: 90 out of 200. The paper is qualifying, and 33% of 200 is 66 marks, so this score clears it.

The arithmetic of guessing

This follows from the rule itself, not from any UPSC statement. With four options, a pure guess is right one time in four on average. Four such guesses would then give one right answer, earning one question's marks, and three wrong ones, costing a third of a question's marks each, so one question's marks in all. On average, nothing is gained and nothing lost. If you can rule out one option and choose among the remaining three, the average turns positive, and it improves as you rule out more. An average says nothing certain about one paper, though: on the day, a run of wrong guesses costs real marks.

Where negative marking doesn't apply

The penalty for wrong answers is for objective-type papers, and the mains papers are essay-type. The notice does allow other deductions in the mains: for handwriting that is not easily legible, for irrelevant matter or marks that could reveal your identity in an answer script, and for misusing the rule that lets you give English versions of technical terms in brackets.

Work out your own score

Enter your right and wrong answers to see your score after the penalty. The same tool has its own page as the prelims score calculator.

For the rest of the exam, see the exam pattern, and to compare a General Studies Paper I score with past qualifying marks, see the UPSC cut-off.