How to Calculate Marks with Negative Marking: Formula and Example

Learning how to calculate marks with negative marking can turn a confusing answer key into a clear final score in a few minutes. Once you know how many questions you got right, how many you got wrong, and the penalty for each wrong answer, the rest is simple subtraction. You do not need to guess, round in your head, or hope that a rough total is close enough, because the method below gives you an exact figure and a useful accuracy percentage as well.

Negative marking is used to discourage blind guessing. A wrong answer does not simply score zero; it takes away part of the credit you earned elsewhere. That is why two students with the same number of correct answers can finish with very different totals. This guide explains the terms one by one, shows the calculation step by step, and finishes with a worked example you can check against the Negative Marking Calculator.

The Method / Formula

The core formula is simple: Final score = (correct answers × marks per correct answer) − (wrong answers × penalty per wrong answer). Accuracy is a separate figure: Accuracy = (correct answers ÷ attempted answers) × 100, where attempted answers = correct answers + wrong answers.

Correct answers are the questions that match the official answer key. Wrong answers are the questions you attempted but got wrong. Marks per correct answer is the credit for one right answer, and the penalty per wrong answer is the deduction for one wrong answer. In many papers the penalty is stated as a fraction, such as one-fourth or one-third of the marks for a question, so check the paper’s scheme before you start.

Unattempted questions are different. A question you leave blank normally scores zero and carries no penalty, so it should not be counted as wrong and should not appear on either side of the formula. Attempted questions are simply correct plus wrong. Accuracy uses attempted questions as its denominator, which is why accuracy can be high even when the final score is modest, if you attempted only a few questions.

Total marks also matter for context. If you know the total for the paper, you can compare your final score with it, but do not use the total as the accuracy denominator. For example, a score of 450 out of 600 is 75% of the total paper, which is a different

figure from accuracy among the questions you actually attempted.

How to Calculate Marks with Negative Marking Step by Step

1. Count your correct and wrong answers against the official answer key, and keep unattempted questions in a separate count.
2. Note the marks for one correct answer and the penalty for one wrong answer from the paper’s marking scheme.
3. Multiply your correct count by the marks per correct answer to get your positive marks.
4. Multiply your wrong count by the penalty per wrong answer to get your total deduction.
5. Subtract the deduction from the positive marks to get your final score, then divide correct answers by attempted answers and multiply by 100 for accuracy.
6. Check the result against the total marks for the paper, and re-count if correct plus wrong plus unattempted does not match the number of questions.

Worked Example

Take the example used on the tool page: 120 correct answers, 30 wrong answers, with +4 marks for each correct answer and −1 mark for each wrong answer. First, work out the positive marks: 120 × 4 = 480. Next, work out the total deduction: 30 × 1 = 30, so the negative marks are −30.

Now subtract: 480 − 30 = 450. The final score is therefore 450 out of 600. For accuracy, first find attempted answers: 120 + 30 = 150. Then divide correct answers by attempted answers: 120 ÷ 150 = 0.80, which is 80.0% accuracy.

The example shows why both figures are worth reading together. A final score of 450 out of 600 tells you where you stand against the paper total, while 80.0% accuracy tells you how clean your attempts were. If accuracy is high but the total is low, you may need to attempt more questions; if accuracy is low, cutting careless errors will usually help more than attempting extra questions.

Common Mistakes / Good to Know

• Counting unattempted questions as wrong. Blank questions normally carry no penalty, so adding them to the wrong count will understate your score.
• Using the wrong penalty for the paper. A +4/−1 scheme is not the same as a scheme that deducts one-third or one-fourth of a question’s marks, so always check the official scheme first.
• Dividing by total questions instead of attempted questions for accuracy. Accuracy is correct divided by attempted, not correct divided by the whole paper.
• Treating a calculator or guide result as the official result. Any figure worked out from an answer key is an estimate; the examining body’s official scorecard is final, and a changed or challenged key can change the outcome.

Frequently Asked Questions

Once you can work out a score this way, try the UPSC Marks Calculator for a paper with its own marking pattern, and read our guide How to Calculate UPSC Prelims Marks next for a worked example from a real exam.