{
    "name": "Exam Negative Marking Calculator",
    "url": "https://calculators.geekmidst.com/calculators/exam-negative-marking-calculator",
    "markdown": "https://calculators.geekmidst.com/calculators/exam-negative-marking-calculator.md",
    "category": "Education",
    "description": "Score a multiple-choice exam with negative marking, see the marks lost to wrong answers and whether a blind guess gains or loses marks on average.",
    "summary": "With negative marking, score = right × marks per right − wrong × penalty. Enter your exam’s marking scheme to see your score and whether guessing pays.",
    "also_called": [
        "MCQ score calculator",
        "Exam marks calculator"
    ],
    "applies_to": "Worldwide",
    "last_updated": "2026-10-29",
    "computation": "Results are computed in the visitor’s browser on the HTML page. This API describes the calculator; it does not compute results.",
    "inputs": [
        {
            "name": "questions",
            "label": "Total questions",
            "type": "number",
            "default": "100"
        },
        {
            "name": "attempted",
            "label": "Questions attempted",
            "type": "number",
            "default": "80"
        },
        {
            "name": "correct",
            "label": "Correct answers",
            "type": "number",
            "default": "60"
        },
        {
            "name": "marks_correct",
            "label": "Marks for a correct answer",
            "type": "number",
            "default": "4"
        },
        {
            "name": "marks_wrong",
            "label": "Marks deducted for a wrong answer",
            "type": "number",
            "default": "1"
        },
        {
            "name": "options",
            "label": "Answer choices per question",
            "type": "number",
            "default": "4"
        }
    ],
    "outputs": [
        {
            "key": "score",
            "label": "Score",
            "format": "number"
        },
        {
            "key": "max_score",
            "label": "Maximum score",
            "format": "number"
        },
        {
            "key": "percentage",
            "label": "Score as % of maximum",
            "format": "percent"
        },
        {
            "key": "wrong",
            "label": "Wrong answers",
            "format": "integer"
        },
        {
            "key": "unattempted",
            "label": "Unattempted",
            "format": "integer"
        },
        {
            "key": "marks_lost",
            "label": "Marks lost to wrong answers",
            "format": "number"
        },
        {
            "key": "accuracy",
            "label": "Accuracy on attempted questions",
            "format": "percent"
        },
        {
            "key": "guess_value",
            "label": "Average marks from a blind guess",
            "format": "number"
        },
        {
            "key": "break_even_accuracy",
            "label": "Accuracy needed to break even",
            "format": "percent"
        }
    ],
    "formula": {
        "text": "Score = Correct × M+ − (Attempted − Correct) × M−;  Guess value = M+ ÷ k − M− × (k − 1) ÷ k;  Break-even accuracy = M− ÷ (M+ + M−)",
        "variables": {
            "M+": "marks for a correct answer",
            "M−": "marks deducted for a wrong answer",
            "k": "answer choices per question"
        }
    },
    "worked_example": {
        "inputs": {
            "questions": "100",
            "attempted": "80",
            "correct": "60",
            "marks_correct": "4",
            "marks_wrong": "1",
            "options": "4"
        },
        "steps": [
            "Wrong = 80 − 60 = 20; score = 60 × 4 − 20 × 1 = 220 of 400 (55%).",
            "A blind guess among 4: 1/4 × 4 − 3/4 × 1 = +0.25 marks on average.",
            "Break-even accuracy = 1 ÷ (4 + 1) = 20%."
        ],
        "result": "60 right and 20 wrong under +4/−1 marking scores 220 of 400; even a blind guess gains 0.25 marks on average."
    },
    "interpretation": "If you can rule out even one option, your chance of being right rises and guessing becomes more worthwhile. Answer whenever your confidence is above the break-even accuracy.",
    "assumptions": [
        "Each question has exactly one correct option and unattempted questions score zero."
    ],
    "limitations": [
        "Sections with different marking schemes need to be calculated separately and added."
    ],
    "rules": null,
    "faqs": [
        {
            "question": "Should I guess with negative marking?",
            "answer": "Guess when your chance of being right is above M− ÷ (M+ + M−). With +4/−1 that is 20%, so a blind guess among four options (25%) just pays off."
        },
        {
            "question": "What does accuracy mean here?",
            "answer": "Correct answers as a share of questions you attempted, which shows how careful your attempts were."
        }
    ],
    "sources": [],
    "related": [
        {
            "name": "Quiz Accuracy Calculator",
            "url": "https://calculators.geekmidst.com/calculators/quiz-accuracy-calculator"
        },
        {
            "name": "Grade Boundary Calculator",
            "url": "https://calculators.geekmidst.com/calculators/grade-boundary-calculator"
        },
        {
            "name": "Percentage Grade Calculator",
            "url": "https://calculators.geekmidst.com/calculators/percentage-grade-calculator"
        }
    ],
    "disclaimer": null,
    "publisher": "GM¹X CalcVerse"
}