Test Grade Calculator (EZ Grader)
Enter the total number of questions and how many were wrong. Your percentage and letter grade appear instantly — plus a full grading-scale table.
The total number of questions on the test.
How many questions were answered incorrectly.
Full Grading Scale
Every possible score for the current total number of questions.
| Wrong | Correct | Percent | Grade |
|---|
How to Calculate a Test Grade
The E-Z Grader is a classic physical grading wheel that teachers have used for decades to convert the number of wrong answers into a percentage and letter grade without doing long division by hand. This digital calculator works the same way: enter the total and the number wrong, and the result appears instantly — no paper wheel needed.
The Formula
percent = ((total − wrong) ÷ total) × 100
Where total is the number of questions on the test and wrong is the number answered incorrectly. The result is rounded to one decimal place.
Letter Grade Scale
The calculator applies the standard 10-point letter-grade scale used by the majority of US schools:
- A — 90% and above
- B — 80%–89%
- C — 70%–79%
- D — 60%–69%
- F — below 60%
Worked Example
A student takes a 20-question test and gets 3 wrong:
percent = ((20 − 3) ÷ 20) × 100
percent = (17 ÷ 20) × 100 = 85% — B
The full grading-scale table above the fold shows all 21 possible scores for a 20-question test, from 0 wrong (100% A) to 20 wrong (0% F), so you can grade an entire class without re-entering values.
Tips for Teachers
- Speed-grade a stack: Enter the total once, then tap − or + as you move through papers — the result updates instantly.
- Print the table: The grading-scale table renders clearly for print. Use it as a reference sheet while marking without a device nearby.
- Different test lengths: Change the total for each new test; the table and result both update immediately.
Frequently Asked Questions
How does the EZ Grader calculate my test score?
The EZ Grader uses the formula: percent = ((total questions − wrong) ÷ total questions) × 100. For example, if a test has 25 questions and you missed 3, the score is ((25 − 3) ÷ 25) × 100 = 88%. The letter grade is then assigned using a standard 10-point scale (A ≥ 90%, B ≥ 80%, C ≥ 70%, D ≥ 60%, F below 60%).
What grading scale does this calculator use?
The calculator uses a standard 10-point grading scale: A (90–100%), B (80–89%), C (70–79%), D (60–69%), and F (below 60%). This scale is used by the majority of US schools. If your school uses a different scale (such as 7-point or plus/minus grading), you can still use the percentage shown and apply your school's scale manually.
Can I use this for any number of questions?
Yes. Enter any total from 1 to 200 (or more) and any number of wrong answers from 0 up to the total. The grading scale table updates instantly to show every possible score for that test length, so you can quickly look up any result without re-entering values.
What is the difference between questions wrong and questions missed?
For this calculator, 'questions wrong' means any question that was not answered correctly — including omitted or blank answers. If your test scores blanks as wrong, count them in the 'wrong' field. If blanks are not penalised (no wrong-answer penalty), enter only the number of incorrect answers.
How do teachers use an EZ Grader?
Teachers traditionally used a physical EZ Grader wheel to quickly convert the number wrong into a percentage and letter grade for a stack of tests. This digital version does the same thing instantly: enter the total number of questions, then use the +/− buttons to scroll through wrong counts and read off scores. The full grading table also prints cleanly so you can use it as a reference sheet while marking.
Does the calculator handle partial credit?
The standard EZ Grader method assumes each question is worth an equal number of points with no partial credit. If your test uses partial credit, you will need to calculate the total points earned manually and convert to a percentage yourself (points earned ÷ total points × 100).