Test Score Calculator
Quick presets:
Use + / - buttons for rapid grading
Optional — adds to your correct count (can push score above 100%)
See how many wrong answers you can afford
Enter Your Test Details
Fill in the total questions and wrong answers (or points earned) above to instantly see your percentage score, letter grade, and full grade breakdown table.
How to Use the Test Score Calculator
Choose Your Input Mode
Select 'Wrong Answers' if you know how many questions were missed, or 'Points Earned' for raw-score or weighted exams. Also choose your grading scale — Simple (A/B/C/D/F) or Extended (with +/- modifiers).
Enter the Test Details
In Wrong Answers mode, type the total number of questions and the number incorrect. Use the quick preset buttons (10, 20, 25, 50, 100) to set common totals, and the +/- buttons to step through wrong answer counts one at a time — great for grading a stack of tests.
Review Your Score and Grade
Your percentage score, letter grade, and correct/total fraction appear instantly. The donut chart and score-position bar show where your score sits on the grading scale. Bonus points can be added to credit extra-credit questions.
Use the Grade Table and Reverse Calculator
Scroll down to see every possible wrong-answer count and its resulting grade — highlighted on the row matching your current score. Use the Desired Grade dropdown to find out the maximum number of questions you can miss and still achieve your target grade.
Frequently Asked Questions
How do I calculate a test score percentage?
Divide the number of correct answers by the total number of questions, then multiply by 100. For example, if you answered 17 out of 20 questions correctly, the calculation is (17 ÷ 20) × 100 = 85%. If you prefer to think in terms of wrong answers, subtract them from the total first: 20 – 3 wrong = 17 correct, then 17 ÷ 20 × 100 = 85%. This calculator handles both approaches automatically — just choose your input mode and type in the numbers.
What is the difference between the Simple and Extended grading scales?
The Simple scale uses five letter grades: A (90–100%), B (80–89%), C (70–79%), D (60–69%), and F (below 60%). It is commonly used in primary school and some secondary school settings. The Extended scale adds plus and minus modifiers to each letter, creating 13 grade levels from A+ (97–100%) down to F (below 60%). The extended scale is standard in most high schools and universities and gives a finer measure of performance — the difference between a strong B+ (87–89%) and a solid B (83–86%) is meaningful when calculating GPA.
How does the reverse calculator work?
The reverse calculator tells you the maximum number of wrong answers you can afford while still earning a specific letter grade. It works by finding the minimum percentage required for your desired grade, then calculating how many correct answers that minimum requires. For example, on a 25-question test, to earn a B (80%) you need at least 20 correct answers, meaning you can miss at most 5 questions. Select your desired grade from the dropdown and the answer updates instantly. This is useful for pre-exam planning — you can see exactly how much margin you have before dropping to a lower grade.
Can my score be higher than 100%?
Yes, if your teacher offers bonus or extra credit questions, your effective correct count can exceed the total number of required questions. In the calculator, enter the number of bonus questions you answered correctly in the Bonus / Extra Credit field. The calculator adds them to your correct count before computing the percentage, so a score of 22 correct out of 20 questions (with 2 bonus) would yield 110%. Many grading systems allow this to reward exceptional effort, though some cap the final grade at 100% — check with your instructor if you are unsure.
What does the grade breakdown table show?
The grade breakdown table lists every possible wrong-answer count from zero (a perfect score) up to the total number of questions. For each row, it shows how many questions would be correct, the resulting percentage, and the letter grade. The row matching your current wrong-answer count is highlighted for easy reference. This table is especially useful for teachers who want to see the full distribution of possible outcomes before grading, and for students who want to understand the boundaries between grade levels on a specific exam.
How do I use this calculator to grade multiple tests quickly?
Set the total number of questions using the preset buttons (or type it in), then use the plus button next to the wrong-answers field to step through counts one at a time. After recording each grade, tap the minus button if needed or hit Reset to return to zero wrong answers. This workflow mimics the QuickGrade-style rapid grading approach where a teacher holds the paper, counts the marks, and taps plus once for each wrong answer to see the grade immediately. The grade breakdown table also allows you to look up any wrong-answer count without changing the inputs at all.