Test Grade Calculator
Your details
Result
Percentage
- Letter grade
- B
- Score
- 42 out of 50
- Each question is worth
- 2% per question
- Incorrect
- 8 incorrect
- For the next grade up
- B+ needs 44 correct (87%)
- With 50 questions each one is worth 2% — so a single careless mistake moves the grade by 2 points. On a 20-question test each answer is worth 5%, which is why short tests swing grades far more than long ones.
- 44 correct would have been B+ — 2 more than you scored.
Scores around yours
What each additional correct answer is worth on a test of this length.
| Correct | Percentage | Grade |
|---|---|---|
| 38 | 76% | C |
| 39 | 78% | C+ |
| 40 | 80% | B− |
| 41 | 82% | B− |
| 42 (yours) | 84% | B |
| 43 | 86% | B |
| 44 | 88% | B+ |
| 45 | 90% | A− |
| 46 | 92% | A− |
Letter grade scale
A common US scale. Institutions differ — some use a 10-point scale with no plus or minus, and some set different cut-offs entirely.
| Grade | Percentage | Correct answers |
|---|---|---|
| A+ | 97% and above | 49+ |
| A | 93–96% | 47+ |
| A− | 90–92% | 45+ |
| B+ | 87–89% | 44+ |
| B (yours) | 83–86% | 42+ |
| C+ | 77–82% | 39+ |
| C | 73–76% | 37+ |
| D+ | 67–72% | 34+ |
| D | 63–66% | 32+ |
| F | 0–62% | — |
How do you calculate a test grade?
Divide the number of correct answers by the total number of questions and multiply by 100. Scoring 42 out of 50 gives 42 ÷ 50 = 0.84, which is 84% — a B on a standard US letter scale.
percentage = (correct ÷ total) × 100 per question = 100 ÷ total- correct
- Answers right, or points earned if questions differ in weight
- total
- Questions asked, or total points available
- 100 ÷ total
- What one question is worth, which sets how much a mistake costs
The percentage is a single division, so the useful part of this calculation is what sits around it. The figure worth knowing is what one question is worth: on a 50-question test each answer is 2%, but on a 20-question quiz each is 5%, which means short tests swing a grade two and a half times harder per mistake. That is why a single careless error on a short quiz can cost a letter grade while the same error on a final barely registers. Letter bands are the other half, and they are not universal. The scale here is a common US one with plus and minus gradations at roughly three-point intervals, but plenty of institutions use a flat ten-point scale, and some set 93 rather than 90 as the A threshold. Check the syllabus rather than assuming. Curves come in two shapes that behave quite differently: adding flat points lifts every score equally, while scaling to the top score divides by the highest paper in the class instead of by the total — which lifts percentages without changing the ranking, and helps most in the middle of the distribution.
- Count the correct answers or the points you actually earned.
- Divide that by the total questions or points available.
- Multiply by 100 to express the result as a percentage.
- Look the percentage up on your institution's letter scale.
- Divide 100 by the total to see what one question is worth.
Worked example: Scoring 42 out of 50 on a test, no curve
Scoring 42 out of 50 on a test, no curve
Dividing 42 by 50 gives 0.84, so the score is 84%, which lands in the B band on a standard US scale — above the 83% cut-off but below the 87% that would make it a B+. With 50 questions each one is worth 100 ÷ 50 = 2%, so the eight wrong answers cost exactly 16 percentage points. That per-question figure is the useful one: three more correct answers would have given 45 out of 50, which is 90% and an A−, so an A− was three correct answers away rather than some vague improvement. Two more than you scored, at 44, gives 88% and a B+. Note how much the test length matters here. The same proportion of mistakes on a 20-question quiz — missing 16% of the questions, so about three of them — would also give 84%, but each individual answer would be worth 5% rather than 2%, so one extra careless error would drop it to 79% and a C+.
What each test grade input means
- Correct answers
- How many you got right. Half marks are allowed — enter 42.5 if that is what you scored.
- Total questions
- The number of questions, or the total points available if questions are worth different amounts.
- Curve
- A points curve adds a flat number of marks. A scaled curve divides by the highest score in the class, so the top paper becomes 100%.
- Points to add
- Used with a points curve. Added to your raw score before the percentage is taken.
- Highest score in the class
- Used with a scaled curve. Your score is divided by this instead of by the total.
What this test grade does not account for
- Letter grade cut-offs are not universal. Some institutions use a flat ten-point scale with no plus or minus, and some set the A threshold at 93% rather than 90%. The syllabus governs.
- If questions carry different weights, use total points rather than question count. A test with 50 questions worth 100 points needs the points as the denominator.
- A points curve adds a flat number of marks to everyone, lifting all scores equally. A scaled curve divides by the top paper, which lifts percentages but cannot change the ranking.
- Rounding policy varies and matters at a boundary. 89.5% may round to 90% and an A− or stay a B+, depending on the institution.
- Extra credit can take a score above the total. This calculation rejects that by default rather than assuming it is allowed.
- A single test is rarely the course grade. Weighted categories across the term are what determine the final result.
- Scantron and auto-marked tests occasionally misread answers. If a score looks wrong, the paper is worth checking against the answer key.
Frequently asked questions
What grade is 42 out of 50?
84%, which is a B on a standard US letter scale. It sits above the 83% B threshold and below the 87% needed for a B+. Each question on a 50-question test is worth 2%.
What percentage is a passing grade?
Usually 60% for a D− or 70% for a C− depending on the institution and whether a course requires a C to count toward a major. Check the syllabus rather than assuming.
How much is each question worth?
Divide 100 by the number of questions. On a 50-question test each is worth 2%; on a 20-question quiz each is 5%, so short tests penalise individual mistakes far more heavily.
What is the difference between a points curve and a scaled curve?
A points curve adds a flat number of marks to every score. A scaled curve divides each score by the highest in the class, lifting percentages without changing anyone's rank.
How many questions do I need right to get an A?
Ninety percent of the total on most scales, so 45 out of 50. Some institutions set the A threshold at 93%, which would require 47 — worth confirming before relying on it.
Does 89.5% round up to an A?
It depends entirely on the institution's rounding policy, and plenty do not round at all. At a grade boundary this is worth asking about rather than assuming.
Sources and review
Last reviewed .