How to calculate a test grade
A test grade is simply the share of available points you earned:
Grade (%) = points earned ÷ total points × 100
If you know how many you got wrong instead, subtract the points lost from the total first. The calculator converts the percentage into a letter grade and shows how many more points would have reached the next 10% band.
Worked example
You scored 42 out of 50 points.
- 42 ÷ 50 × 100 = 84%
- On the standard scale, that is a B
- Reaching 90% (an A−) would have needed 45 points, 3 more
On a 25-question quiz with 4 wrong answers: 21 ÷ 25 = 84%, the same B.
Standard US letter grade scale
| Letter | Percentage | GPA (4.0 scale) |
|---|---|---|
| A+ | 97–100 | 4.0 |
| A | 93–96 | 4.0 |
| A− | 90–92 | 3.7 |
| B+ | 87–89 | 3.3 |
| B | 83–86 | 3.0 |
| B− | 80–82 | 2.7 |
| C+ | 77–79 | 2.3 |
| C | 73–76 | 2.0 |
| C− | 70–72 | 1.7 |
| D+ | 67–69 | 1.3 |
| D | 63–66 | 1.0 |
| D− | 60–62 | 0.7 |
| F | below 60 | 0.0 |
Schools and teachers can set their own cutoffs, so check your syllabus. Some colleges give an A+ the value 4.3, and some high schools weight honors and AP courses on a 5.0 scale.
Grading tips for teachers
- Points per question: for a test where questions carry different weights, add up the points rather than counting questions.
- Partial credit: the calculator accepts quarter points, so half-credit answers are easy to include.
- Curving: a simple curve adds the same number of points to everyone so the top score reaches 100%; a more cautious approach adds a fixed percentage.
- Extra credit can push a score above 100%; the calculator still reports the percentage correctly.
From one test to a course grade
A single test is usually one part of a weighted course grade. To see how a test affects your overall grade, or what you need on the final exam to reach a target, combine the results with a weighted average.