Negative Marking Calculator
Work out your exam score with negative marking, and whether guessing pays off.
What is negative marking?
In an exam with negative marking, each wrong answer takes marks away, and unattempted questions score zero. The penalty is meant to discourage random guessing. It is usually a fraction of the marks for a question, such as 1/4, 1/3 or 1/2, or a fixed amount, such as −1 on a 4-mark question.
The negative marking formula
Score = (correct answers × marks per correct answer) − (wrong answers × penalty per wrong answer)
For 100 one-mark questions with 70 correct, 20 wrong and 10 unattempted, and a penalty of 1/4 mark, the score is 70 − 20 × 0.25 = 65 out of 100 (65%). Your accuracy, correct answers out of those attempted, is 77.8%.
| Penalty per wrong answer | Marks deducted | Score |
|---|---|---|
| None | 0 | 70 |
| 1/4 mark | 5 | 65 |
| 1/3 mark | 6.67 | 63.33 |
| 1/2 mark | 10 | 60 |
| 1 mark (equal) | 20 | 50 |
How to use the calculator
- My score: enter the number of questions, your correct and wrong answers, the marks per correct answer and the penalty. It shows your score, percentage, marks deducted, unattempted questions and accuracy.
- Should I guess?: enter the number of options and the penalty to see the expected marks from a guess, and the chance of being right that you need to break even.
- Marks I need: enter how many questions you will attempt and your target score, and see how many correct answers you need and how many wrong answers you can afford.
Is guessing worth it?
A guess is worth it if your chance of being right is higher than penalty ÷ (1 + penalty), where the penalty is a fraction of the marks. With four options and a 1/4 penalty, a blind guess has a 25% chance of being right, above the 20% break-even, so it gains about 0.06 marks on average. With a 1/3 penalty, the break-even is exactly 25%, so a blind guess neither gains nor loses on average. With a 1/2 penalty, blind guessing loses marks.
| Penalty | Chance you need | Blind guess among 4 options |
|---|---|---|
| 1/4 | 20% | Gains 0.0625 marks on average |
| 1/3 | 25% | Break-even (0 marks) |
| 1/2 | 33.3% | Loses 0.125 marks on average |
| 1 (equal) | 50% | Loses 0.5 marks on average |
If you can rule out one of four options, your chance rises to 33.3%, and with a 1/4 penalty a guess gains about 0.17 marks on average. Over many questions, ruling out options is what makes guessing pay off, so a calculation like this is a guide, and it does not guarantee a result on any one question.
Examples of marking schemes
These are commonly published schemes. Exams change their rules from year to year, so always check the official notice for your test.
| Exam type | Marks for a correct answer | Penalty for a wrong answer |
|---|---|---|
| NEET UG and JEE Main (multiple choice) | +4 | −1 |
| UPSC prelims, general studies | +2 | −0.66 (1/3) |
| SSC CGL, tier 1 | +2 | −0.5 |
| Bank prelims, such as IBPS and SBI | +1 | −0.25 |
| CAT (multiple choice) | +3 | −1 |
| GATE, 1-mark questions | +1 | −1/3 |
Many other tests, including several university entry tests in Pakistan, use different rules or no negative marking at all. Use the official instructions to find the correct marks and penalty, and enter them in the calculator.
Frequently asked questions
How do I calculate negative marking?
Multiply your correct answers by the marks per question, then subtract the number of wrong answers multiplied by the penalty. Unattempted questions score zero.
How do I calculate 1/4 negative marking?
Divide the number of wrong answers by 4 and subtract the result from the number of correct answers. With 70 correct and 20 wrong, the score is 70 − 20 ÷ 4 = 65.
How do I calculate 1/3 negative marking?
Subtract one third of a mark for each wrong answer. With 70 correct and 20 wrong, the score is 70 − 20 ÷ 3 = 63.33.
Do unattempted questions lose marks?
No. Only wrong answers are penalised, and unattempted questions score zero.
How do I find my percentage with negative marking?
Divide your net score by the maximum marks and multiply by 100. A score of 65 out of 100 is 65%.
Should I guess when there is negative marking?
Only if your chance of being right is above the break-even point, which is penalty ÷ (1 + penalty). With a 1/4 penalty it is 20%, so ruling out some options makes guessing worthwhile.
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