Test Grade Calculator
Calculator
EZ-grader reference table
| Wrong | Score | Grade |
|---|---|---|
| 0 | 100% | A |
| 1 | 95% | A |
| 2 | 90% | A |
| 3 | 85% | B |
| 4 | 80% | B |
| 5 | 75% | C |
| 6 | 70% | C |
| 7 | 65% | D |
| 8 | 60% | D |
| 9 | 55% | F |
| 10 | 50% | F |
| 11 | 45% | F |
| 12 | 40% | F |
| 13 | 35% | F |
| 14 | 30% | F |
| 15 | 25% | F |
| 16 | 20% | F |
| 17 | 15% | F |
| 18 | 10% | F |
| 19 | 5% | F |
| 20 | 0% | F |
About this calculator
This calculator converts a raw test score — questions answered correctly (or wrongly) out of a total — into a percentage and a standard letter grade. It works like the classic "EZ Grader" teachers keep on their desks: enter any combination of correct answers and total questions, and the result appears instantly. An optional curve field lets you add bonus points before the letter grade is assigned.
How to read your results
The headline figure is your percentage score for the inputs you entered. The letter grade (A/B/C/D/F) appears directly below it, colour-coded for quick reading. Below the result card, the EZ-grader reference table lists every possible number of wrong answers for the same total, showing the corresponding percentage and letter grade for each row; your current score is highlighted in the table so you can see how one or two extra correct answers would change the grade.
How it's calculated
The percentage score is computed as percent = (correct / total) × 100 + curvePts, clamped to the interval [0, 100]. The letter grade is then assigned using the standard five-band scale: a percentage of 90 or above earns an A, 80–89 a B, 70–79 a C, 60–69 a D, and anything below 60 an F. These cutoffs follow the most widely used US grading scale, documented in the sources listed below. The full reference table is generated by iterating wrong from 0 to total, computing correct = total − wrong for each step, and applying the same formula to produce a row of (wrong, percent, letter) for every possible outcome.
Worked example
18 correct answers out of 20 total questions, no curve.
18 ÷ 20 × 100 = 90.0%, which falls in the A band (90–100). The reference table shows that missing just one more (17/20 = 85.0%) would drop the grade to a B.
| Letter | Percent range | Meaning |
|---|---|---|
| A | 90–100% | Excellent |
| B | 80–89% | Good — above average |
| C | 70–79% | Average |
| D | 60–69% | Below average — minimal pass |
| F | Below 60% | Failing |
| Questions | 1 wrong | 2 wrong | 3 wrong | 4 wrong | 5 wrong |
|---|---|---|---|---|---|
| 10 | 90.0% | 80.0% | 70.0% | 60.0% | 50.0% |
| 12 | 91.7% | 83.3% | 75.0% | 66.7% | 58.3% |
| 15 | 93.3% | 86.7% | 80.0% | 73.3% | 66.7% |
| 20 | 95.0% | 90.0% | 85.0% | 80.0% | 75.0% |
| 25 | 96.0% | 92.0% | 88.0% | 84.0% | 80.0% |
| 30 | 96.7% | 93.3% | 90.0% | 86.7% | 83.3% |
| 40 | 97.5% | 95.0% | 92.5% | 90.0% | 87.5% |
| 50 | 98.0% | 96.0% | 94.0% | 92.0% | 90.0% |
Frequently asked questions
How is the percentage calculated?
The formula is simply (correct ÷ total) × 100. If you enter wrong answers instead, the calculator converts them first: correct = total − wrong. Any curve points are then added to the raw percentage, and the result is clamped to a maximum of 100.
What are the letter-grade cutoffs?
The calculator uses the standard US scale: 90–100 → A, 80–89 → B, 70–79 → C, 60–69 → D, and below 60 → F. This is the most common scale in US schools and colleges, though individual institutions may shift the cutoffs — the sources at the end of the page document the standard bands and their variants.
What does the curve field do?
Curve points are added directly to the raw percentage after dividing correct by total. For example, a 5-point curve on a 70% raw score gives 75%, raising the grade from a C to a C (just under B). Curve points are capped so the final percentage never exceeds 100.
Can I use this for partial or weighted scoring?
This calculator assumes every question is worth one point. For tests with different point values per question, use a weighted-grade calculator instead and enter total points earned versus total points possible.
How do I read the EZ-grader reference table?
Each row in the table represents a different number of wrong answers for the total you entered. Read across to see the resulting percentage and letter grade. Your own score is highlighted. The table makes it easy to tell students — or yourself — exactly how many correct answers are needed for each grade band.
What grade is 15 out of 20?
15 out of 20 is 75% (15 ÷ 20 × 100), a C on the standard US scale. The same method works for any score: divide correct answers by total questions and multiply by 100. A few common ones: 17/20 = 85% (B), 18/20 = 90% (A), 21/25 = 84% (B), 27/30 = 90% (A).
How do I score a test that penalizes wrong answers (negative marking)?
Exams with negative marking — common in multiple-choice entrance exams and the Spanish oposiciones — subtract a fraction of a point per wrong answer, usually 1/(k − 1) where k is the number of answer options. The score is correct − wrong / (k − 1), then scaled to the exam maximum; blank answers usually cost nothing. Example with 100 four-option questions: 70 correct, 20 wrong and 10 blank give 70 − 20/3 = 63.3 points. This calculator assumes no penalty, so compute the penalized points first and enter them as correct answers out of the total.
What percentage do I need to pass a test?
On the US letter scale used here, anything at 60% or above avoids an F, but most courses set their own pass marks — 70% is a common requirement in US college courses and certification exams. Grading systems abroad set different bars: Spain passes at 5 out of 10 (50%), Mexico at 6 out of 10, Portugal at 10 out of 20, and Brazilian schools commonly require an average of 6 or 7 out of 10. Always check the syllabus or exam rules that actually apply.
Popular scenarios
Sources
- Academic grading in the United States — Wikipedia
- Grading – First-Year Writing Program — The University of Alabama
- Academic grading in Spain — Wikipedia
- Academic grading in Mexico — Wikipedia
- Academic grading in Russia — Wikipedia
- Academic grading in Portugal — Wikipedia
- Grading systems by country — Wikipedia
- Multiple choice — Wikipedia
- BOE-A-2003-17643 Real Decreto 1125/2003, de 5 de septiembre, por el que se establece el sistema europeo de créditos y el sistema de calificaciones en las titulaciones universitarias de carácter oficial y validez en todo el territorio nacional. — Boletín Oficial del Estado
Reviewed by the YouCalc Team · Last reviewed
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