Test Grade Calculator (EZ Grader)
This test grade calculator turns a raw score into a percentage and letter grade instantly. Enter the total number of questions and how many were wrong to see your grade — plus a full grading-scale table.
Last updated July 2026
The total number of questions on the test.
How many questions were answered incorrectly.
Grading scale
Your choice is saved for every tool on this site.
Set the minimum % for each letter grade. Changes apply instantly.
Scale used: A 90+ · B 80–89 · C 70–79 · D 60–69 · F below 60
Grading scales vary by school — check your syllabus, and adjust the scale above if yours differs.
Full Grading Scale
Every possible score for the current total number of questions.
| Wrong | Correct | Percent | Grade |
|---|
How to Calculate a Test Grade
A test grade is calculated by dividing the number of correct answers by the total number of questions, then multiplying by 100 to get a percentage.
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 Examples
Example 1 — a standard test. 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. If a test was unusually difficult, see the Grade Curve Calculator to adjust a whole set of scores at once instead of grading each one manually.
Example 2 — an odd total. A 15-question vocabulary quiz with 2 missed:
percent = ((15 − 2) ÷ 15) × 100
percent = (13 ÷ 15) × 100 ≈ 86.7% — B
One more wrong answer (3 of 15) drops the score to 80% — the very bottom of the B band — so a single question is the difference between a solid B and slipping toward a C.
Why Short Tests Swing So Hard
On any test, each question is worth 100 ÷ total percentage points. A short 8-question pop quiz makes that painfully clear — every item is worth 12.5 points:
- Miss 1 of 8 → 87.5% (B)
- Miss 2 of 8 → 75% (C)
- Miss 3 of 8 → 62.5% (D)
The same three-question slip that costs a 20-question test a single letter grade costs the 8-question quiz two. That's why the scale table is most valuable on small tests: the jump between adjacent rows is largest there, and a borderline paper can land on either side of a letter cutoff.
Common Grading Pitfalls
- Bonus questions inflate the denominator. If a test has 25 scored questions plus 2 extra-credit items, enter 25 as the total, not 27 — then add the bonus in your gradebook afterwards. Rolling the bonus into "total questions" quietly lowers everyone's percentage.
- Decide your rounding rule first. A raw 89.6% is a B until you round it to 90%. Pick whether you round, and to how many places, before you start marking so every borderline paper is treated the same way.
- Unequal question values break the method. The EZ-Grader math assumes every question is worth the same. A test that mixes 1-point and 5-point items needs the Points-Based Grade Calculator instead.
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).