Quiz Grade Calculator: Score, Percentage, and Letter Grade
Enter how many you got right and how many questions there were, and see the percentage, the letter grade, and the grade for every number you could have missed. This quiz grade calculator does the arithmetic teachers do by hand, and shows the whole grading chart instead of one number.
- Grade is correct divided by total, times 100. Pick the letter scale (plain A to F, or with plus and minus).
- The chart gives the grade for every number wrong, so you can see what one more right answer is worth before you argue for it.
- A short quiz is a noisy grade. Ten questions carry a margin of error near twenty-five points, which the tool spells out.
Your quiz grade
7 out of 10 is 70%, a C. Pass, at or above 60%
What you would get for each number wrong
| Wrong | Right | Score | Grade |
|---|---|---|---|
| 0 | 10 | 100% | A |
| 1 | 9 | 90% | A |
| 2 | 8 | 80% | B |
| 3 | 7 | 70% | C |
| 4 | 6 | 60% | D |
| 5 | 5 | 50% | F |
| 6 | 4 | 40% | F |
| 7 | 3 | 30% | F |
| 8 | 2 | 20% | F |
| 9 | 1 | 10% | F |
| 10 | 0 | 0% | F |
Highlighted row is your score. Each wrong answer costs 10 points here, so the fewer questions a quiz has, the more a single miss moves the grade.
The grade for every number wrong
Most percentage tools give you one number and stop. The chart in the quiz grade calculator above gives the grade for zero wrong, one wrong, two wrong, all the way down, for a quiz of whatever length you enter. That is the number people actually want, because the real question is rarely "what is 14 out of 20" and usually "if I can flip one more answer, does my grade change letters?"
The reason the chart matters is that a single question is worth more on a short quiz than a long one. On a ten-question quiz each item is ten points, so one miss is the difference between an A and a B. On a fifty-question exam each item is two points, and one miss barely moves you. Same one wrong answer, very different cost, entirely because of how many questions there are.
The letter grade behind the percentage
A percentage becomes a letter through a scale, and there is no single official one. These two are the common US conventions. Each band runs from its lower number up to, but not including, the next one, so an 89.5% is still a B unless your instructor rounds it up. Your school sets the real cutoffs, so treat this as the usual case, not a law.
| Standard scale | Range | With plus / minus | Range |
|---|---|---|---|
| A | 90 to 100 | A+ | 97 to 100 |
| B | 80 up to 90 | A | 93 up to 97 |
| C | 70 up to 80 | A- | 90 up to 93 |
| D | 60 up to 70 | B+ | 87 up to 90 |
| F | under 60 | B | 83 up to 87 |
| B- | 80 up to 83 | ||
| C+ | 77 up to 80 | ||
| C | 73 up to 77 | ||
| C- | 70 up to 73 | ||
| D+ | 67 up to 70 | ||
| D | 63 up to 67 | ||
| D- | 60 up to 63 | ||
| F | under 60 |
How to calculate a quiz grade
The whole calculation is one division. Take the number of questions you answered correctly, divide by the total number of questions, and multiply by 100. That gives the percentage, and the scale above turns the percentage into a letter. The tool just runs this instantly and draws the chart, but the math is short enough to do on the back of the quiz.
Correct divided by total, times 100
If you got 18 right on a 25-question quiz, that is 18 divided by 25, which is 0.72, times 100, so 72%. A C on the standard scale. The one thing people get wrong here is counting: make sure "total" is every question that counted, including any you left blank, not just the ones you attempted.
When questions are weighted differently
Not every quiz gives each question the same value. If a short answer is worth 5 points and a multiple choice is worth 1, you cannot just count questions. Add up the points you actually earned and divide by the total points the quiz was out of. Points earned over points possible, times 100, is the same formula with points standing in for question counts.
Rounding: does 89.5% become an A?
Sometimes, and it is a judgment call your instructor makes, not arithmetic. Some round 89.5% up to a 90 and an A, some round to the nearest whole percent, some do not round at all and 89.9% stays a B. The calculator shows the percentage to a decimal place, before any rounding to a whole grade, so you know which side of a boundary you landed on and whether it is worth asking about.
Why one short quiz is a noisy grade
Here is the thing the big grade calculators leave out. A single short quiz is a small sample, and small samples are noisy. Treat your score as an estimate of how much you actually know, and that estimate has a margin of error, the same way a poll of ten people does. For a ten-question quiz, the 95% margin of error around a 7 out of 10 is roughly plus or minus 25 points. In plain terms, a 7 out of 10 cannot reliably tell an A-level grasp from a C-level one.
This comes straight from the arithmetic of a proportion. The tool uses the Wilson score interval, a standard way to put error bars on a percentage that, unlike the simpler textbook version, does not claim zero uncertainty when you go a perfect 10 for 10. It is still an approximation, and the fewer questions there are, the wider it gets, which is exactly when you should trust one quiz least. More questions shrink it fast: 35 out of 50, also 70%, has a margin near 12 points, and 70 out of 100 near 9.
The practical takeaway is not to obsess over one quiz. If a grade matters, the fix is more questions and more than one sitting. That is the whole reason a practice quiz you can regenerate beats a single graded one: you get a bigger, repeated sample of the same material.
Questions people ask about grading a quiz
What grade is 7 out of 10?
Seven correct out of ten is 70%, which is a C on the standard A to F scale (and a C- on a plus/minus scale). Each question on a ten-item quiz is worth ten points, so three wrong drops you exactly thirty points from a perfect score.
How do I calculate a quiz grade?
Divide the number you got right by the total number of questions, then multiply by 100. Eight right out of twenty is 8 divided by 20, which is 0.4, times 100, so 40%. If different questions are worth different points, add up the points you earned and divide by the points possible instead.
Is 70% a passing grade?
It depends on the passing line the class sets. Many US courses treat 60% (a D) as the lowest passing grade, so 70% passes comfortably. Some programs, nursing and some graduate courses in particular, set the line at 70% or higher, in which case 70% is right on the edge. The pass line switch above lets you check against 50, 60, or 70.
How much is each question worth on a 20-question quiz?
On an equally weighted 20-question quiz, each question is worth 100 divided by 20, which is 5 points. So every wrong answer costs 5 percentage points: one wrong is 95%, two wrong is 90%, four wrong is 80%.
What is my grade if I got 3 wrong out of 15?
Three wrong out of fifteen means twelve right, and 12 divided by 15 is 0.8, so 80%. That is a B on the standard scale. The chart in the tool lays out the grade for every number wrong on a quiz of whatever length you enter.
What letter grade is 85%?
On the standard A to F scale 85% is a B, since B covers 80 to 89. On a plus/minus scale 85% is a B (the B band runs 83 to 86), a point below a B+ and two above a B-. Scales are set by the school or instructor, so check your syllabus if the cutoffs matter.
Does a quiz grade round up?
That is a policy, not a rule of arithmetic. Plenty of instructors round 89.5% up to a 90 and an A, and plenty do not round at all. Neither is more correct. The calculator shows the percentage to a decimal place, before any rounding to a whole grade, so you know which side of the line you are on.
How many can I get wrong and still pass?
Take your passing percentage, multiply by the number of questions, and round up to get the minimum you need right. To pass a 10-question quiz at 60% you need 6 right, so you can miss up to 4. To pass a 25-question quiz at 70% you need 18 right, so you can miss up to 7.