Quiz Grade Calculator | Percentage, Letter Grade & Miss Chart
Find your quiz grade the moment you finish grading — enter correct answers or points earned and this quiz grade calculator instantly shows your percentage, letter grade, and exactly how many questions you could afford to miss for each grade level.
Calculate Your Quiz Grade
Score needed for each grade (out of 20)
Quick answer: Quiz % = (Correct ÷ Total Questions) × 100, or for point-based quizzes, Quiz % = (Points Earned ÷ Points Possible) × 100.
Example: 17 correct out of 20 = 85% (B). Extra credit is usually added to points earned before dividing, which can push a score above 100%.
What Is a Quiz Grade Calculator?
A quiz grade calculator converts a raw score — correct answers out of a total, or points earned out of points possible — into a percentage and letter grade in one step. It's built for a single quiz, test, or exam, which is different from a current grade calculator that combines several graded categories into one overall course grade.
How to Calculate Your Quiz Grade
Count your correct answers, or add up the points you earned if questions carry different values.
Note the total number of questions, or the total points possible on the quiz.
Add any extra credit points to what you earned.
Divide what you earned by the total possible, then multiply by 100.
Compare the percentage to your class's letter-grade scale.
Quiz Grade Formulas
By Questions
(Correct ÷ Total Questions) × 100By Points
(Points Earned ÷ Points Possible) × 100Use the questions version when every question is worth the same amount. Use the points version when questions carry different point values, when partial credit is allowed, or when your teacher's gradebook already shows a points total.
Worked Examples
| Score | Calculation | Percentage | Letter Grade |
|---|---|---|---|
| 17 out of 20 | 17 ÷ 20 × 100 | 85% | B |
| 34 out of 50 | 34 ÷ 50 × 100 | 68% | D+ |
| 7 wrong out of 40 | (40 − 7) ÷ 40 × 100 | 82.5% | B- |
| 9 out of 10 | 9 ÷ 10 × 100 | 90% | A- |
How Many Questions Can You Miss?
The calculator above generates a live chart the moment you enter your total questions: it lists the minimum correct answers needed for an A, B, C, and D on that specific quiz, so you can see exactly how much room you have. This kind of lookup is sometimes called an EZ grader chart in classrooms, and the math behind it is simple: multiply the grade cutoff (like 90% for an A) by the total questions, then round up.
For a 20-question quiz on a common 90/80/70/60 scale: an A needs at least 18 correct, a B needs at least 16, a C needs at least 14, and a D needs at least 12 — meaning up to 8 wrong still passes. Enter your own total above to get the exact numbers for your quiz.
Quiz Grade vs. Test Grade vs. Current Grade
| Quiz Grade | Current Grade | |
|---|---|---|
| Covers | One quiz, test, or exam | Every graded category in the course |
| Input | Correct answers or points | Category averages and weights |
| Use it to | Check one score right after grading | Check where you stand in the whole class |
| Related tool | Test Grade Calculator | Current Grade Calculator |
Extra Credit and Passing Grades
Most teachers add extra credit points directly to points earned before dividing by the original points possible, which is why a score can land above 100% — the calculator above follows this common method. A smaller number of teachers instead add the bonus to both earned and possible points, which keeps the maximum at 100%; check your class's policy if the two methods would change your grade meaningfully.
60% is a widely used minimum passing grade in U.S. schools, but it is set by the school or instructor, not a universal rule — some courses set the bar at 65% or 70% instead. Carnegie Mellon's teaching center and the University of Kentucky's own grading FAQ both confirm that grade cutoffs are set by the instructor or department, not fixed nationally (sources below).
Letter Grade Reference Scale
This is a common U.S. reference scale. Confirm your own teacher's cutoffs before treating a result as official.
| Letter | Percentage | Letter | Percentage |
|---|---|---|---|
| A+ | 97–100% | C+ | 77–79% |
| A | 93–96% | C | 73–76% |
| A- | 90–92% | C- | 70–72% |
| B+ | 87–89% | D+ | 67–69% |
| B | 83–86% | D | 63–66% |
| B- | 80–82% | D- | 60–62% |
| F | Below 60% | ||
Related Calculators
Test Grade Calculator
Score a full exam with the same percentage and letter-grade math.
Current Grade Calculator
Combine quizzes, tests, and homework into one course grade.
Final Grade Calculator
Find the score you need on what's left to reach a target grade.
Percentage to GPA Calculator
Convert a 0–100% average to a 4.0-scale GPA.
GPA to Percentage Calculator
Convert a 4.0-scale GPA back to a percentage.
Middle School GPA Calculator
Roll your class grades up into an overall GPA.
Frequently Asked Questions
How do you calculate a quiz grade?
Divide the number of correct answers by the total number of questions, then multiply by 100. For quizzes graded by points instead of question count, divide points earned by points possible and multiply by 100.
What is the formula for quiz percentage?
Quiz Percentage = (Correct Answers ÷ Total Questions) × 100. If some questions are worth different amounts, use Quiz Percentage = (Points Earned ÷ Points Possible) × 100 instead.
How many questions can I miss and still get an A, B, or C?
It depends on the total number of questions and your teacher's grading scale. On a common 90/80/70/60 scale, an A generally needs at least 90% correct, a B at least 80%, and so on. Enter your quiz's total question count into the calculator above to see the exact number for each grade.
Does extra credit affect my quiz percentage?
Yes. Extra credit points are typically added to your points earned before dividing by the original points possible, which can push your percentage above 100%. Some teachers instead add extra credit points to both earned and possible points — check your teacher's method.
What percentage is passing on a quiz?
60% is a common minimum passing grade in U.S. schools, corresponding to a D. Some schools and courses set the passing bar at 65% or 70% instead, so check your syllabus or student handbook.
What's the difference between a quiz grade calculator and a current grade calculator?
A quiz grade calculator scores one quiz or test from correct answers or points. A current grade calculator combines many graded categories, like quizzes, tests, and homework, into one overall course grade using their assigned weights.
Sources
- Carnegie Mellon University, Eberly Center — grading scales are instructor- or department-set, not universally fixed
- University of Kentucky, Department of Chemistry — confirms grade cutoffs are set per course, not by university-wide rule
