UPSC Prelims Marks Calculator
(GS Paper I + CSAT with 1/3 Negative Marking)
Enter your correct and wrong answers for GS Paper I and CSAT to get your marks with one-third negative marking and check the CSAT qualifying mark.
General Studies Paper I (100 questions, 2 marks each)
Each wrong answer costs one-third of 2 marks
CSAT Paper II (80 questions, 2.5 marks each)
Each wrong answer costs one-third of 2.5 marks
Result
💡 Formula Guide
How the UPSC Prelims Marking Scheme Works
The UPSC Civil Services Preliminary Examination has two objective papers: General Studies Paper I with 100 questions worth 200 marks, and the Civil Services Aptitude Test (CSAT) with 80 questions worth 200 marks. Both carry one-third negative marking, and the two papers play different roles. GS Paper I decides whether you clear the Prelims cut-off for the Mains, while CSAT is a qualifying paper that you must pass with at least 33%. A UPSC marks calculator therefore has to treat the two papers separately, which is what this page does.
| Paper | Questions | Marks per question | Total | Negative marking | Role |
|---|---|---|---|---|---|
| General Studies Paper I | 100 | 2 | 200 | One-third of 2 marks per wrong answer | Counted for the Prelims cut-off |
| CSAT (Paper II) | 80 | 2.5 | 200 | One-third of 2.5 marks per wrong answer | Qualifying: at least 33% |
Example. On GS Paper I, 62 correct and 24 wrong answers give 124 − 16 = 108 marks. On CSAT, 45 correct and 20 wrong answers give 112.5 − 16.7 = 95.8 marks, comfortably above the 66-mark qualifying line. Notice how much a wrong GS answer costs: it wipes out a third of a correct answer's worth, so 24 wrong answers cost as much as 8 correct ones would have earned.
The CSAT Qualifying Rule
CSAT is qualifying in nature, which means its marks are not added to your merit score, but you must reach 33% of the total, which is 66 marks out of 200, for your GS Paper I to be evaluated for the cut-off. Some websites state the mark as 66.67 because they take one-third of 200; the published rule is 33%, and the calculator uses 66. Because CSAT has 80 questions at 2.5 marks with one-third negative marking, a candidate with about 30 correct answers and few wrong ones clears it, though the exact number depends on how many answers are wrong.
⚠️ Do not ignore CSAT. Candidates with strong GS scores have missed the Mains because of CSAT. If your CSAT result in the calculator is close to 66, review it carefully against a reliable answer key.
Reading Your Result Correctly
The calculator's main figure is your GS Paper I score, but a score alone does not tell you whether you cleared the Prelims. UPSC announces the cut-off with the result each year, and it depends on the difficulty of the paper and the category of the candidate, so it changes. Compare your marks with cut-offs from previous years for your category, and remember that answer keys published by coaching institutes can differ on a handful of questions. A few disputed answers can move your total by several marks, so run the calculator with each plausible key and note the range.
Rounding is another source of small differences. Working with exact thirds, a wrong GS answer costs 0.667 marks; a site that rounds to 0.66 or 0.67 will show a total that differs slightly for large numbers of wrong answers. Treat the estimate as accurate to a fraction of a mark and keep a margin when comparing with a cut-off.
Using the Numbers to Improve
If you are reviewing a mock test, look at accuracy as well as score. With one-third negative marking, guessing is only worth it when your chance of being right exceeds 25%. Our Negative Marking Calculator shows your break-even accuracy and the expected value of a blind guess, which helps you decide how aggressively to attempt doubtful questions. Track marks lost to negative marking across several mocks: if it is large compared with your unattempted count, you may be guessing too freely.
Other exam tools on this site include the Grade Calculator and the CGPA Calculator. Always confirm the current exam pattern and marking scheme in the official UPSC notification, because patterns are revised from time to time.
Frequently Asked Questions About UPSC Prelims Marks
How are UPSC Prelims marks calculated?
General Studies Paper I has 100 questions worth 2 marks each, so 200 marks in total. Each wrong answer loses one-third of the marks assigned to that question. Marks = 2 × correct − (2 ÷ 3) × wrong. Unattempted questions score zero. With 62 correct and 24 wrong, the score is 124 − 16 = 108.
How is the CSAT scored?
CSAT (Paper II) has 80 questions worth 2.5 marks each, for 200 marks in total, with one-third negative marking. It is a qualifying paper: you need at least 33% to have your GS Paper I evaluated for the cut-off.
What is the CSAT qualifying mark?
33% of 200, which is 66 marks. Some sources quote 66.67 because they treat 33% as one-third, but the rule is 33%. The calculator uses 66 and shows your CSAT marks against it.
Do CSAT marks count toward the Prelims cut-off?
No. Only GS Paper I marks are used to decide who qualifies for the Mains, as long as CSAT is passed. That is why the calculator's main result is the GS score and CSAT is reported as a pass or fail check.
What is the UPSC Prelims cut-off?
UPSC announces the cut-off with the Prelims result each year, and it varies by year and category depending on the difficulty of the paper. The calculator deliberately does not use a fixed cut-off; compare your marks with the cut-offs published for previous years and the answer key you use.
Why does my total differ from a coaching website's?
Because of rounding. One-third of 2 marks is 0.6667, and many sites round it to 0.66 or 0.67. The calculator uses the exact fraction, so a long list of wrong answers can differ from another site's total by a few tenths of a mark.
How many questions should I attempt?
Under one-third negative marking, guessing is worth it only when your chance of being right exceeds 25%. A blind guess among four options has zero expected value, while each option you can eliminate improves the odds. Use the Negative Marking Calculator to see the break-even for your own accuracy.
Is the result official?
No. It is an estimate for self-evaluation based on an answer key you trust. The official result comes from UPSC.
Last Updated: September 2026 | Marking scheme reflects UPSC Civil Services Prelims as widely published (GS: 100 questions, 2 marks; CSAT: 80 questions, 2.5 marks; 1/3 negative marking; CSAT 33% qualifying). Confirm details in the current UPSC notification.