EZ Grader Online: Free Easy Grader Calculator for Teachers
An EZ grader (or easy grader) turns the number of wrong answers on a test into a percentage and letter grade. This free online version works for any test length, with half points, plus/minus grades and printable charts, so you don't need a paper slide chart.
- Free, no sign-up
- Any test length up to 1,000
- Plus/minus or letters-only
- Half points
- Scores stay in your browser
- No ads
Quick answer: percentage = (correct ÷ total) × 100. On a 20-question test, 2 wrong answers is 90%, an A-.
Free easy grader calculator
Use this EZ Grader calculator (also called an easy grader calculator or EZ grade calculator) to turn test scores and wrong answers into a percentage and letter grade.
Keyboard shortcuts: press W to add a wrong answer or R to reset when you are not typing in a field.
Common sizes: 10, 20, 25, 30, 50, 100. You can also enter total points.
How many questions the student missed.
18 of 20 correct (2 wrong). Outstanding result.
ezgradercalc.com · Standard (A+ to F, with + and −)
Grading chart for a 20-question test
Every possible score for this test, so you can grade a whole stack without a calculator.
| Wrong | Correct | Score | Grade |
|---|---|---|---|
| 0 | 20 | 100% | A+ |
| 1 | 19 | 95% | A |
| 2 | 18 | 90% | A- |
| 3 | 17 | 85% | B |
| 4 | 16 | 80% | B- |
| 5 | 15 | 75% | C |
| 6 | 14 | 70% | C- |
| 7 | 13 | 65% | D |
| 8 | 12 | 60% | D- |
| 9 | 11 | 55% | F |
| 10 | 10 | 50% | F |
| 11 | 9 | 45% | F |
| 12 | 8 | 40% | F |
| 13 | 7 | 35% | F |
| 14 | 6 | 30% | F |
| 15 | 5 | 25% | F |
| 16 | 4 | 20% | F |
| 17 | 3 | 15% | F |
| 18 | 2 | 10% | F |
| 19 | 1 | 5% | F |
| 20 | 0 | 0% | F |
The math runs in your browser, so the scores you type aren't sent anywhere. Need a course grade instead of one test? Try the final grade calculator.
How to use this grading calculator for teachers
It works for any test length, from a 10-question quiz to a 100-point exam. Three quick steps, and the result updates as you type:
- 1. Enter the test size
Type the number of questions, or the total points for a point-based test.
- 2. Enter how many were missed
Count whichever is smaller, wrong or correct, and use the switch to match.
- 3. Read the grade
The percentage, letter grade and GPA points update as you type.
Grading a whole stack of the same test? Print the chart under the result, or open the chart for your test length from the printable EZ grader charts, then read each grade from one row.
Why teachers use this easy grader
Grading by hand is mostly small arithmetic, and small arithmetic is where tired people make mistakes. This test score calculator takes that step off your plate and shows its working, so you can trust the number and move on.
The arithmetic is done for you
Enter the test size and the number wrong. The calculator subtracts, divides and multiplies, so the slips that come with grading by hand, such as a dropped digit or a wrong division, don't happen. You still count the wrong answers, so a quick second look at the paper is worth it.
Plus/minus or plain letters
Switch between the common U.S. plus/minus scale and a letter-only scale. Cutoffs are applied to the exact score, so 89.6% is a B+, not an A-.
Percentage, letter and GPA at once
Every result shows the test score percentage to two decimals, the letter grade and the 4.0-scale GPA points, plus a chart of every possible score for that test length.
Half points and point-based tests
Count by half points for partial credit, or enter total points instead of questions when the questions aren't worth one point each.
Private by design
The calculation runs in your browser. The scores you type aren't sent to a server, and there is no account to create.
One set of rules everywhere
The calculator, the printable charts and the guides all use the same grading logic, and the worked examples on this site are calculated by it, so one page can't quietly disagree with another.
Want to know who is behind the site and how the numbers are checked? Read the about page, or see how data is handled in the privacy policy.
Quick answers: score by number of questions missed
The most common test sizes on the standard plus/minus scale. Find your test length, then read across. Need every score for a test, or a printable version? Use the printable EZ grader charts.
New to grading tests, or dealing with a curve, extra credit or partial credit? Read how to grade a test.
| Test size | 1 wrong | 2 wrong | 3 wrong | 5 wrong |
|---|---|---|---|---|
| 10 questions | 90% (A-) | 80% (B-) | 70% (C-) | 50% (F) |
| 20 questions | 95% (A) | 90% (A-) | 85% (B) | 75% (C) |
| 25 questions | 96% (A) | 92% (A-) | 88% (B+) | 80% (B-) |
| 30 questions | 96.67% (A) | 93.33% (A) | 90% (A-) | 83.33% (B) |
| 50 questions | 98% (A+) | 96% (A) | 94% (A) | 90% (A-) |
| 100 questions | 99% (A+) | 98% (A+) | 97% (A+) | 95% (A) |
The formula, with three worked examples
Every easy grader runs the same three steps: subtract the wrong answers to get the correct count, divide by the total, and multiply by 100. The letter grade then comes from your scale, which is a lookup, not a formula.
Whole questions
25-question quiz, 4 wrong
Correct = 25 − 4 = 21
Percent = 21 ÷ 25 × 100 = 84%
Grade = B
With half points
30-question test, 3.5 wrong
Correct = 30 − 3.5 = 26.5
Percent = 26.5 ÷ 30 × 100 = 88.33%
Grade = B+
Point-based test
50 points, 7 points lost
Earned = 50 − 7 = 43
Percent = 43 ÷ 50 × 100 = 86%
Grade = B
Grading scales you can choose
The default is the U.S. plus/minus scale. Some schools use plain letters instead, so the calculator lets you switch. For GPA points and weighted GPA, see the full grading scale guide.
| Letter | Score |
|---|---|
| A+ | 97–100% |
| A | 93–96% |
| A- | 90–92% |
| B+ | 87–89% |
| B | 83–86% |
| B- | 80–82% |
| C+ | 77–79% |
| C | 73–76% |
| C- | 70–72% |
| D+ | 67–69% |
| D | 63–66% |
| D- | 60–62% |
| F | Below 60% |
| Letter | Score |
|---|---|
| A | 90–100% |
| B | 80–89% |
| C | 70–79% |
| D | 60–69% |
| F | Below 60% |
Borderline scores and rounding
This calculator applies cutoffs to the exact score. A student with 89.6% on a 100-point test gets a B+ on the plus/minus scale, not an A-, because the score is below 90.
Many teachers round borderline scores up (for example, 89.5% to 90%) and others never do. There is no universal rule, so follow your syllabus or department policy. If you do round, round once, at the very end, and never round the percentage before you apply the cutoff, because that can push a score across a line it has not actually crossed.
Common scores, answered
A lookup for the "what is X out of Y" questions that come up most, on the plus/minus scale.
| Score | Percentage | Letter grade | Missed |
|---|---|---|---|
| 7 out of 10 | 70% | C- | 3 |
| 8 out of 10 | 80% | B- | 2 |
| 9 out of 10 | 90% | A- | 1 |
| 12 out of 15 | 80% | B- | 3 |
| 13 out of 15 | 86.67% | B | 2 |
| 14 out of 15 | 93.33% | A | 1 |
| 15 out of 20 | 75% | C | 5 |
| 16 out of 20 | 80% | B- | 4 |
| 17 out of 20 | 85% | B | 3 |
| 18 out of 20 | 90% | A- | 2 |
| 19 out of 20 | 95% | A | 1 |
| 20 out of 25 | 80% | B- | 5 |
| 21 out of 25 | 84% | B | 4 |
| 22 out of 25 | 88% | B+ | 3 |
| 23 out of 25 | 92% | A- | 2 |
| 24 out of 25 | 96% | A | 1 |
| 24 out of 30 | 80% | B- | 6 |
| 27 out of 30 | 90% | A- | 3 |
| 28 out of 30 | 93.33% | A | 2 |
| 40 out of 50 | 80% | B- | 10 |
| 45 out of 50 | 90% | A- | 5 |
| 75 out of 100 | 75% | C | 25 |
| 85 out of 100 | 85% | B | 15 |
| 90 out of 100 | 90% | A- | 10 |
Grading a whole stack faster
The calculator is best for one paper at a time. For a full class set, a printed chart is faster, since you only count the wrong answers and read the grade off one row.
- Open the chart for your test length and print it, or save it as a PDF.
- Mark each paper, and write the number of wrong answers at the top.
- Look up that number on the chart and write the percentage and letter next to it.
- Spot-check a few papers with the calculator, especially ones near a cutoff.
- Enter the finished scores into your gradebook, which is the system of record.
Mistakes that cause wrong grades
- Entering correct answers in the wrong box. Check the Wrong / Correct switch before you type.
- Using the wrong total. If a question is worth 2 points, enter total points, not questions.
- Forgetting extra credit. A score above 100% needs your own handling; this tool caps the wrong count at the test size.
- Mixing scales. A 90 is an A on a letter-only scale and an A- on a plus/minus scale.
- Averaging percentages. Tests of different sizes should be weighted, not averaged. Use the weighted average calculator.
What this tool does and does not do
It converts a raw score into a percentage and letter grade for one test. It is not a gradebook: it does not keep records, track students, or send anything to a server. If you need the grade for a whole course, or the score required on a final exam, use the final grade calculator or read how to calculate your grade after the final.
Last reviewed: October 2026.
Printable charts by test length
Pick your test length for a chart with the percentage and letter grade for every score, plus half points for tests up to 30 questions.
Frequently asked questions
How does an EZ grader work?
An EZ grader, also called an easy grader, turns the number of questions a student missed into a percentage and a letter grade. You enter the test size and the number wrong. It subtracts to get the number correct, divides by the total and multiplies by 100. For example, 2 wrong on a 20-question test is 18 ÷ 20 × 100 = 90%, an A- on the standard plus/minus scale.
How do I calculate test grades without a calculator?
Work out what one question is worth by dividing 100 by the number of questions, multiply that by the number wrong, and subtract the result from 100. On a 25-question test each question is 4%, so 3 wrong costs 12 points and the score is 88%, a B+. For a whole class set, print the chart for your test length and read each grade from one row.
What is 18 out of 20 as a percentage?
18 out of 20 is 90%, which is an A- on the standard plus/minus scale and an A on a letter-only scale where 90% to 100% is an A.
Does it work for any test length?
Yes, up to 1,000 questions or points. Enter the total, whether it is a 5-question quiz, a 40-question test or a 100-point exam, and the chart below the result rebuilds for that length. For many common lengths there is also a printable chart page.
Does it support plus and minus letter grades?
Yes. The default is the common U.S. plus/minus scale (A+ at 97%, A at 93%, A- at 90%, B+ at 87%, B at 83%, and so on down to D- at 60%). You can switch to a letter-only scale where 90% is an A, 80% a B, 70% a C and 60% a D. Schools and teachers set their own cutoffs, so follow your syllabus if it differs.
Can I grade with half points or total points?
Yes to both. Switch Count by to Half points and the buttons and the chart move in 0.5 steps: on a 30-question test, 3.5 wrong answers is 88.33%, a B+. For a point-based test, enter the total points as the test size and the points lost as the wrong amount: a 50-point test with 7 points lost is 86%, a B.
Is it free, and do I need an account?
It is free and needs no account or sign-up. The site doesn't show ads.
Does it store student scores?
No. The calculation runs in your browser, so the numbers you type are not sent to a server. Avoid typing student names anyway; the tool does not need them.
Is there a difference between EZ grader and easy grader?
No. They are two names people use for the same kind of tool: enter the test size and the number missed, and read off the percentage and letter grade.
Does it work outside the United States?
The percentage is universal, but the letter grades follow the U.S. scale. Schools in the UK, Canada and Australia often use different bands or no letters at all, so use the percentage and apply your own institution's boundaries.
What does easy grader mean?
An easy grader, also written EZ grader, turns the number of wrong (or correct) answers on a test into a percentage and letter grade. The name is also used for paper slide charts that do the same job. This page is the online version, and it works for any test length.
Is there an app called EZ Grader?
Several tools use the name, including paper slide charts and websites. This calculator needs no download or account. It runs in your phone or computer browser.
Is 27 out of 40 a pass?
27 out of 40 is 67.5%, a D+ on the plus/minus scale. That clears a 60% pass mark. A 70% pass mark would need 28 correct. Pass marks vary by school, so check yours.
Is 67% a D+?
Yes: on the standard plus/minus scale, 67% is a D+. On a letter-only scale, anything from 60% to 69% is a D. Schools set their own cutoffs.