Calculate your exam percentage from marks obtained and total marks.
Percentage = (marks obtained ÷ total marks) × 100.
In exams with negative marking — the standard format for JEE Main/Advanced, NEET, and most Indian competitive exams — your percentage is not simply correct answers divided by total questions. Wrong answers actively subtract from your score, so two students who answer the exact same number of questions correctly can end up with meaningfully different percentages depending on how many wrong answers they also picked up. A commonly cited illustration: two students both get 140 questions correct, but one has 20 wrong answers while the other has 35 — under JEE Main's typical +4/-1 scheme, that difference in wrong answers alone creates a real, exam-relevant gap between their final scores, even though their "correct answer count" looks identical.
This is exactly why accuracy, not just attempt count, is the metric serious aspirants track — attempting more questions only helps if the additional attempts are accurate enough to outweigh the negative marking cost of the wrong ones. A common benchmark used in coaching is that once your accuracy on mock tests drops below roughly 75%, attempting more questions is likely to hurt your score more than help it, and the better strategy is to focus attempts on questions you're genuinely confident about rather than guessing to maximize raw attempt count. Since exam-specific marking schemes vary (JEE Main uses +4/-1 for MCQs, JEE Advanced uses penalties up to -2 on certain question types, and integer-type questions sometimes have no negative marking at all), it's worth confirming your specific exam's exact scheme before assuming a generic +4/-1 calculation applies.
Because negative marking means wrong answers subtract points, not just fail to add them. Your actual score (and therefore percentage) depends on both how many you got right and how many you got wrong — two students with the identical number of correct answers can have meaningfully different final percentages if their wrong-answer counts differ.
Typically +4 for a correct answer and -1 for a wrong answer on standard MCQs. JEE Advanced can carry steeper penalties (up to -2) on certain question types, and integer-type or numerical-answer questions sometimes carry no negative marking at all. Always confirm the specific scheme for the exam and question type you're preparing for, since it varies.
Accuracy matters more once you factor in negative marking — attempting additional questions only helps your score if you're accurate enough on them to outweigh the penalty from any wrong guesses. A commonly used benchmark is that mock-test accuracy below roughly 75% suggests you should prioritize revising concepts over attempting more questions.
Potentially significantly — in exams like JEE and NEET where large numbers of candidates cluster around similar scores, even a small score difference from wrong-answer penalties can shift your rank meaningfully. This is exactly why accuracy-focused preparation (and knowing when to skip an uncertain question rather than guess) is emphasized so heavily by exam coaches.