How to grade a test quickly
- Enter the total number of questions (or total points).
- Enter how many the student got wrong — or switch to “Number correct”.
- Read the percentage and letter grade. The chart below lists the score for every possible number of wrong answers, so you can grade a whole stack of papers without recalculating.
The formula
Score (%) = (Total − Wrong) ÷ Total × 100. For a 25-question quiz with 3 wrong: 22 ÷ 25 × 100 = 88% (B+).
Each question’s value
On a 25-question test each question is worth 4%; on a 20-question test, 5%; on a 40-question test, 2.5%. Knowing this helps students understand how much a single mistake costs, and helps teachers design tests where one error doesn’t drop a full letter grade.
Letter grade scale
| Letter | Percent | 4.0 scale |
|---|---|---|
| A+ / A | 93–100% | 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 |
The most common US scale. Schools and teachers may use different cut-offs — check your syllabus.
Tips for teachers
- Print or keep the chart open while grading — just find the number wrong and read across.
- For tests with different point values per question, enter total points and points lost instead of questions.
- To combine test scores into a class grade, use the weighted grade calculator.
Frequently asked questions
How do I calculate a test score percentage?
Divide the number of correct answers by the total number of questions and multiply by 100.
What is 20 out of 25 as a grade?
80%, which is a B− on the common US scale.
Can I use points instead of questions?
Yes. Enter the total points and the points lost (or earned).
Is this like the EZ Grader?
Yes — the chart works like a paper EZ Grader, showing the score for every number of wrong answers.