Quiz Score Percentage Calculator — Grade Instantly
Turn a raw quiz score into a percentage and letter grade from correct answers and total questions.
Reviewed by Daniel Agrici, Founder & Lead Developer
Formula
Percentage = (Correct Answers x Points Per Question + Bonus) / (Total Questions x Points Per Question) x 100
Where Correct Answers is the number of questions answered correctly, Points Per Question is the point value for each question, Bonus is any additional bonus points earned, and Total Questions is the total number of questions on the quiz. The result is the percentage score.
Worked Examples
Example 1: Basic Quiz Score Calculation
Problem:A student answered 17 out of 20 questions correctly on a biology quiz. Each question is worth 5 points. What is their percentage and letter grade?
Solution:Correct answers: 17 out of 20\nPoints earned: 17 x 5 = 85 points\nTotal points: 20 x 5 = 100 points\nPercentage: (85/100) x 100 = 85%\nLetter grade: B (83-86% range)\nGPA value: 3.0\nIncorrect answers: 3
Result:85% = B (3.0 GPA) | 85/100 points | 3 incorrect
Example 2: Quiz with Bonus Points
Problem:A student got 8 out of 10 questions correct (2 points each) plus earned 3 bonus points. What is their adjusted score?
Solution:Correct answers: 8 out of 10\nBase points earned: 8 x 2 = 16 points\nBonus points: 3\nTotal earned: 16 + 3 = 19 points\nMaximum base points: 10 x 2 = 20 points\nAdjusted percentage: (19/20) x 100 = 95%\nLetter grade: A (93%+ range)
Result:95% = A (4.0 GPA) | 19/20 points with bonus
Frequently Asked Questions
How do I calculate my quiz score percentage?
To calculate your quiz score percentage, divide the number of correct answers by the total number of questions and multiply by 100. For example, if you answered 17 out of 20 questions correctly, your percentage is (17 divided by 20) times 100, which equals 85%. If questions have different point values, divide total points earned by total points possible instead. This formula works for any type of quiz regardless of the number of questions. Some instructors also apply partial credit or bonus points, which should be added to your earned points before calculating the percentage.
What is considered a good quiz score?
A good quiz score depends on context, but generally 80% or above is considered good in most educational settings. Scoring 90% or above is typically excellent, indicating strong mastery of the material. In competitive academic environments or STEM courses, even 70% might be acceptable if the class average is low. For professional certifications, passing scores often range from 65% to 80% depending on the exam. What matters most is how your score compares to the learning objectives and whether it demonstrates sufficient understanding to build upon in subsequent material. Consistent improvement over multiple quizzes is more important than any single score.
How do bonus points affect my quiz percentage?
Bonus points are added to your earned points before calculating the percentage, which can push your score above 100%. For example, if you got 9 out of 10 questions correct (90%) but earned 2 bonus points, your adjusted score becomes 11 out of 10, or 110%. However, most gradebooks cap the maximum at 100% when recording the grade. Bonus points are most valuable when you missed regular questions because they can compensate for errors. Some instructors offer bonus questions on quizzes as a way to reward students who engage with extra material without penalizing those who only study the required content.
What is the difference between a quiz and a test in grading?
Quizzes and tests differ primarily in scope, weight, and frequency. Quizzes typically cover recent material from one or two lessons, contain fewer questions (5-20), take less time (10-20 minutes), and carry less weight in the overall grade (5-15% total). Tests or exams cover broader material from an entire unit or semester, contain more questions (30-100+), allow more time (50-180 minutes), and carry significantly more weight (20-40% each). Despite these differences, the percentage calculation method is identical for both. A 90% on a quiz and 90% on an exam are calculated the same way, though their impact on the final grade differs based on weight.
References
Reviewed by Daniel Agrici, Founder & Lead Developer · Editorial policy