This EZ Grader is the easy online grading calculator that replaces the cardboard slide chart on your desk. Enter the total number of questions and the number wrong — the percentage score and letter grade appear as you type, for any test length, including the awkward ones like 43 or 17. It also does what a printed grading chart never could: half points and partial credit, points-earned mode for rubric-scored work, extra credit, a flat curve, your school’s own A–B–C–D cutoffs, a full grading chart you can copy or print, and a running class average as you work through the stack.
Each question is worth 5.00% — miss 2 for an A, 4 for a B, 6 for a C, 8 and you still pass.
Grading scale & curve — match your school’s cutoffs
Default cutoffs are the standard 90 / 80 / 70 / 60 scale. Change any of them and every result, plus every row of the grading chart, follows your policy instead.
Grading chart — every score for this test length
Your current score is highlighted. Copy it into a gradebook or print it for the desk.
| Wrong | Correct | Score | Letter |
|---|
Class average — track the stack as you grade
Press Record & next after each paper. Nothing is uploaded or saved — the list lives in this browser tab only and disappears when you close it.
Every calculation runs in your browser, so no student score leaves your device. Results are estimates for planning; your gradebook and school grading policy are official.
How to Use the Easy Online Grading Calculator
The fast path is two numbers and about four seconds a paper. Everything after step 2 is optional — use it only if your assignment needs it.
- Enter the total number of questions. Type what the test is out of — 10, 15, 20, 25, 43, 100, anything. Set it once for the whole stack; it stays put while you grade. If your assignment has questions worth different amounts, skip to step 6 and use points mode instead.
- Enter the number wrong. The percentage score and letter grade update instantly — there is no submit button and no page reload. Grading a stack? Use +1 wrong to tick up as you mark, rather than counting first and typing after.
- Turn on half points for partial credit. Set the point step to 0.5 or 0.25 and the wrong-answer box takes decimals, so a paper marked “minus 2.5” scores exactly what the student earned instead of being rounded to a neighbouring grade.
- Add extra credit or a curve if your policy allows them. Extra credit points are added to the score, so bonus work can push a paper above 100%. A flat curve adds the same number of percentage points to every score — and to every row of the grading chart.
- Set your school’s grading scale. Open the grading scale panel and enter your own A, B, C and D cutoffs. A 93/85/77/70 district scale grades correctly instead of being forced onto the standard 90/80/70/60, and plus/minus letters switch off for schools that report whole letters.
- Switch to points mode for essays and rubrics. Points-earned mode takes points earned and points possible — 68 out of 80 is 85% — which is the right tool whenever questions are not all worth the same.
- Open the grading chart and grade the whole stack. The chart lists the percentage and letter for every possible number of wrong answers at your test length, with your current score highlighted. Copy or print it and you can mark the rest of the class without touching the keyboard.
- Press Record & next after each paper. The score is added to a running class average with the high and low, and the wrong-answer box clears for the next student — so you finish the stack already knowing whether the test was too hard.
EZ Grader Formula — How a Test Grade Percentage Is Calculated
The whole calculator rests on one line of arithmetic. Subtract the wrong answers, divide by the total, multiply by 100:
Drop the extra credit term and you have the classic version teachers have used for decades: (Correct ÷ Total) × 100. A worked example on a 20-question quiz with 3 marked wrong:
| Step | Working | Result |
|---|---|---|
| Correct answers | 20 − 3 | 17 |
| Fraction correct | 17 ÷ 20 | 0.85 |
| Percentage score | 0.85 × 100 | 85.0% |
| Letter grade (standard scale) | 83–86% band | B |
The other number worth knowing is what a single question is worth: 100 ÷ total questions. On this 20-question quiz that is 5 percentage points per item, which is why the scores jump in clean 5-point steps and why there is no way to score an 87% on it. On a 15-question quiz each item is worth 6.67 points and no whole letter boundary lands cleanly at all — the reason printed charts always looked so strange for odd totals.
EZ Grader Chart — Percentage Scores for 10, 15, 20, 25 and 50 Questions
These are the five test lengths teachers grade most, in one place. For any other total — 12, 43, 60, 150 — open the grading chart inside the calculator above and it builds the full column for you, half-point rows included.
| Wrong | Out of 10 | Out of 15 | Out of 20 | Out of 25 | Out of 50 |
|---|---|---|---|---|---|
| 0 | 100% | 100% | 100% | 100% | 100% |
| 1 | 90% | 93.3% | 95% | 96% | 98% |
| 2 | 80% | 86.7% | 90% | 92% | 96% |
| 3 | 70% | 80% | 85% | 88% | 94% |
| 4 | 60% | 73.3% | 80% | 84% | 92% |
| 5 | 50% | 66.7% | 75% | 80% | 90% |
| 6 | 40% | 60% | 70% | 76% | 88% |
| 7 | 30% | 53.3% | 65% | 72% | 86% |
| 8 | 20% | 46.7% | 60% | 68% | 84% |
| 9 | 10% | 40% | 55% | 64% | 82% |
| 10 | 0% | 33.3% | 50% | 60% | 80% |
Read the table down a column and the cost of a single mistake is obvious: one wrong answer out of 10 removes 10 points, out of 50 it removes 2. That is also the case for using longer assessments when a grade matters — a 50-question exam measures what a student knows, a 5-question quiz mostly measures whether they had a bad morning.
How Many Questions Can You Miss and Still Get an A?
This is the single most searched grading question, and the answer is simply 10% of the question count, rounded down, on a 90% A cutoff:
| Test length | Misses for an A (90%) | Misses for a B (80%) | Misses for a C (70%) | Misses to pass (60%) |
|---|---|---|---|---|
| 10 questions | 1 | 2 | 3 | 4 |
| 15 questions | 1 | 3 | 4 | 6 |
| 20 questions | 2 | 4 | 6 | 8 |
| 25 questions | 2 | 5 | 7 | 10 |
| 30 questions | 3 | 6 | 9 | 12 |
| 40 questions | 4 | 8 | 12 | 16 |
| 50 questions | 5 | 10 | 15 | 20 |
| 100 questions | 10 | 20 | 30 | 40 |
A stricter cutoff roughly halves that allowance. If your school starts the A at 93%, a 20-question quiz allows one miss instead of two, and a 15-question quiz allows exactly one — 93.3%, with nothing to spare. Enter your own cutoffs in the calculator and the line above the results recalculates the allowance for your policy and your test length.
Half Points, Partial Credit and Extra Credit — the Scores Printed Charts Can’t Do
Real grading rarely lands on whole numbers. A student shows the work but reaches the wrong answer; a bonus question is attempted; a rubric awards 1.5 out of 2. A cardboard slide chart forces you to round in the school’s favour or the student’s. This one doesn’t.
- Half points and quarter points: set the point step to 0.5 or 0.25 and enter decimals. A paper marked minus 2.5 on a 30-question test is 27.5 ÷ 30 = 91.7% — an A-, where rounding to 3 wrong would have given 90.0% and rounding to 2 would have given 93.3%, a full letter apart at some schools.
- Extra credit that lifts the score above 100%: leave the total at the required question count and enter the bonus points earned. Two wrong on a 25-question quiz plus 1 extra credit point is (23 + 1) ÷ 25 = 96%.
- Extra credit folded into the total instead: if the bonus questions count toward what the test is out of, add them to the total. Five bonus items on a 50-question test means entering 55; three wrong then gives 52 ÷ 55 = 94.5%. Two policies, two answers — pick the one your syllabus states.
- Rounding stays your decision: results show one decimal place, so 86.67% is not quietly turned into 87%. Tick “round to whole percent” only if your gradebook does.
Points-Earned Mode — Grading an Essay, Rubric or Unequal Test
Wrong-answer mode assumes every question is worth the same. The moment that stops being true — an essay out of 40, a lab report on a 25-point rubric, a test with 10 one-point items and 2 ten-point problems — switch to points earned and enter what the student scored against what the assignment was out of.
| Assignment | Earned | Possible | Score | Letter |
|---|---|---|---|---|
| Essay, 4-trait rubric | 17 | 20 | 85.0% | B |
| Unit test, mixed items | 68 | 80 | 85.0% | B |
| Lab report | 22.5 | 25 | 90.0% | A- |
| Project + 3 bonus points | 44 (+3) | 50 | 94.0% | A |
Getting this wrong is the most common grading error made with an easy grader: entering a 12-question test where question 12 is worth 20 points as “12 questions, 1 wrong” reports 91.7% when the student actually earned 80%. If the items are not equal, use points.
Custom Grading Scale — Set Your Own A, B, C and D Cutoffs
Most online graders hard-code the standard scale and hope your school matches. Plenty don’t: 93/85/77/70 is common in US districts, honors sections often run 94/87/80/73, and many schools report whole letters with no plus or minus at all. Enter your thresholds once in the grading scale panel and the letter grade, the insight line and every row of the grading chart follow them.
| Percentage | Letter | 4.0 GPA points | Meaning |
|---|---|---|---|
| 97–100% | A+ | 4.0 | Excellent |
| 93–96% | A | 4.0 | Excellent |
| 90–92% | A- | 3.7 | Very good |
| 87–89% | B+ | 3.3 | Very good |
| 83–86% | B | 3.0 | Good |
| 80–82% | B- | 2.7 | Good |
| 77–79% | C+ | 2.3 | Satisfactory |
| 73–76% | C | 2.0 | Satisfactory |
| 70–72% | C- | 1.7 | Satisfactory |
| 67–69% | D+ | 1.3 | Below average |
| 63–66% | D | 1.0 | Below average |
| 60–62% | D- | 0.7 | Passing, barely |
| Below 60% | F | 0.0 | Failing |
The GPA column is where a single test score connects to a transcript. One quiz does not move a GPA on its own — it moves the course grade, and the course grade converts to grade points. To follow that chain, use the high school GPA calculator or the college GPA calculator.
Curving a Test — Adding Points Without Breaking the Chart
When a class average comes in lower than the material deserved, the honest fix is usually the simplest one: a flat curve. Enter the number of percentage points to add and every score shifts by the same amount — a 78% becomes an 83%, and the grading chart rebuilds with the curve already applied so you can grade the rest of the stack straight from it.
- Flat curve (supported here): everyone gains the same points. Easy to explain to students and parents, and it never changes class rank.
- Highest-score curve: the top paper is set to 100% and everyone else gains that same difference. It is a flat curve with the amount chosen by one student — enter that difference in the curve field to reproduce it.
- Square-root or bell curves: these compress the top and stretch the bottom, so students who did well gain least. Statistically defensible on a large final, rarely worth the argument on a Tuesday quiz.
When an EZ Grader Is the Wrong Tool
An easy grader answers one question precisely: what percentage is this paper? It does not answer what that paper does to a course grade, and using it for that is where students end up with a nasty surprise in June.
- Course grade across categories: if homework, quizzes and exams carry different percentages of the final grade, that is weighted math — use the weighted grade calculator or the grade calculator.
- What you need on the final: to work backwards from a target course grade to a required exam score, use the final grade calculator.
- Combining quarters with a final exam: that is the semester grade calculator.
- GPA: percentages become grade points before they become a GPA. Start at the GPA calculator hub and pick high school or college.
- Standards-based grading: 4-3-2-1 proficiency scales do not convert to percentages cleanly, and forcing them through a grading calculator misrepresents what the levels mean.