Negative Marking in SSC, IBPS and UPSC: When Should You Guess?
The exact maths of negative marking in SSC, IBPS and UPSC prelims, and a simple rule for when guessing helps your score and when it hurts.
By the World MCQ Forum India Editorial Team · 27 October 2026 · 3 min read
“Should I attempt a question I’m not sure about?” is one of the most common questions before any objective exam. The answer depends on the marking scheme, and it can be worked out exactly. This guide does the maths for three major exams, using the penalties stated in their official notices.
The three marking schemes
| Exam | Marks per question | Penalty per wrong answer | Penalty as a share of the question |
|---|---|---|---|
| SSC CGL / CHSL Tier-I | 2 | 0.50 | one quarter |
| IBPS PO / Clerk prelims | 1 | 0.25 | one quarter |
| UPSC Civil Services prelims | set per paper (each paper is 200 marks) | one third of the question’s marks | one third |
SSC and IBPS look different, but in proportion they are the same: a wrong answer costs a quarter of what a right answer earns. UPSC is stricter, at one third.
The expected value of a guess
Imagine you guess on a question with four options. On average, what do you gain?
SSC (+2, −0.50)
- Pure guess (1 in 4 chance): 0.25 × 2 − 0.75 × 0.5 = 0.5 − 0.375 = +0.125 marks
- After ruling out one option (1 in 3): 0.333 × 2 − 0.667 × 0.5 ≈ 0.667 − 0.333 = +0.33 marks
- After ruling out two options (1 in 2): 0.5 × 2 − 0.5 × 0.5 = 1 − 0.25 = +0.75 marks
IBPS (+1, −0.25)
- Pure guess: 0.25 × 1 − 0.75 × 0.25 = +0.0625 marks
- One option ruled out: ≈ 0.333 − 0.167 = +0.17 marks
- Two options ruled out: 0.5 − 0.125 = +0.375 marks
UPSC prelims (+M, −M/3, where M is the marks for the question)
- Pure guess: 0.25 × M − 0.75 × M/3 = 0.25M − 0.25M = exactly zero
- One option ruled out: 0.333 × M − 0.667 × M/3 ≈ +0.11 M
- Two options ruled out: 0.5 × M − 0.5 × M/3 ≈ +0.33 M
What the numbers tell you
- In SSC and IBPS, even a blind guess has a slightly positive average. But “average” hides the risk: guess on 20 questions and you could easily lose marks on the day. Blind guessing adds luck to your score, not skill.
- In UPSC, a blind guess gains exactly nothing on average. It only adds risk. Guess only when you can rule something out.
- Ruling out even one option changes everything. In every exam, a guess becomes clearly worthwhile once you can eliminate one or two choices. This is the skill to practise.
A simple rule for exam day
- Know it: answer.
- Can rule out two options: answer. The odds are strongly in your favour.
- Can rule out one option: answer in SSC and IBPS; in UPSC, answer if you have a reasonable hunch.
- No idea at all: usually skip, especially in UPSC. In SSC and IBPS, skip unless you need a few extra marks to clear a sectional cut-off.
Practise eliminating, not just answering
Most candidates practise by checking whether their first answer is right. Try this instead: for each question, cross out the options you are sure are wrong before choosing. You will notice that many “guesses” are really 50–50 choices, which the maths above shows are well worth taking.
Our mock test lets you turn negative marking on or off, so you can see exactly how your guessing habits change your score. Try one paper with your usual approach and one with the rule above, then compare.
Marking schemes are taken from the official SSC scheme of examination, the IBPS CRP notifications and the UPSC Civil Services notification. Always check the notice for your own exam, as schemes can change.