How negative marking works, and how to calculate your likely score

A candidate finishes SSC CGL Tier 1 certain they have done well: eighty questions attempted, sixty correct. Then the result comes back lower than expected, because twenty wrong answers were quietly subtracting marks the whole time. Negative marking is not complicated arithmetic, but it is arithmetic almost nobody does calmly during an actual exam, which is exactly when it matters most.

The basic rule

Most SSC, banking and railway exams deduct a fraction of a mark for every wrong answer, on top of not awarding a mark for it. The fraction differs by exam:

• A quarter mark (0.25) per wrong answer is common in railway and several SSC exams.
• A half mark (0.50) per wrong answer applies to SSC CGL and CHSL Tier 1.
• A third of a mark (0.33) applies to some RRB exams.

There is no universal figure. The exact penalty for any exam is stated in its own notification, and this site’s exam pages list it under exam pattern for that reason. Never assume one exam’s penalty applies to another.

The arithmetic, worked through

Take SSC CGL Tier 1: two marks per question, a 0.50 mark penalty per wrong answer, one hundred questions.

Suppose you attempt eighty questions and get sixty right, twenty wrong.

• Marks for correct answers: 60 × 2 = 120
• Marks deducted for wrong answers: 20 × 0.50 × 2 = 20
• Net score: 120 − 20 = 100

That twenty wrong answers cost exactly twenty marks, the same as if you had left ten more questions blank instead of guessing on them. This is the number that matters when deciding whether to guess: on this exam, four wrong guesses cost the same as leaving two questions blank.

When guessing is worth it

The decision is not “never guess,” it is “guess only when your odds beat the penalty.” If you can eliminate two of four options and guess between the remaining two, you have a genuine 50% chance of being right. On SSC CGL’s structure, a coin flip guess between two options has a positive expected value: half the time you gain 2 marks, half the time you lose 1 mark (the 0.50 penalty on a 2 mark question), for an average gain of 0.5 marks per guess.

A pure blind guess among four options, with no elimination at all, is close to break-even or negative depending on the exact penalty fraction, which is why blind guessing across an entire section rarely helps and sometimes actively hurts.

Do the maths before the exam, not during it

The point of understanding this in advance is that you should never be doing this calculation in your head with the clock running. Decide your guessing strategy beforehand: for this exam’s specific penalty, how many options do I need to eliminate before a guess makes sense. Write that number down as part of your preparation, not as something you reason through mid-exam.

The negative marking calculator on this site does the arithmetic instantly: enter your total questions, attempted, correct answers, marks per question and the penalty fraction for your specific exam, and it returns your net score and the marks lost to wrong answers. Use it after every mock test to see exactly how many marks your wrong answers are costing you, not just how many you got wrong.

Check the actual penalty for your exam

Before you rely on any of the figures above, confirm the exact negative marking fraction and marks per question for the specific exam and stage you are sitting. Every exam page on this site lists the pattern, including the negative marking fraction, sourced from the official notification. Treat a number from memory or from a previous year as a guess, not a fact, until you have checked it against the current notification.