How this EZ grader works
This is a classic EZ grader: it subtracts the number wrong from the total questions to get the number correct, then divides by the total and multiplies by 100. Score = (questions − wrong) ÷ questions × 100.
How to use it
Enter the number of questions on the test and how many the student got wrong. The result updates instantly with the percentage and letter grade — handy for grading a stack of papers. If questions are worth different points, use the grade percentage calculator. To attach a letter to the percentage, use the letter grade calculator.
Quick reference
On a 25-question test: 1 wrong = 96% (A), 3 wrong = 88% (B+), 5 wrong = 80% (B-), 8 wrong = 68% (D+). Each missed question is worth 100 ÷ questions percent — 4% here.
Notice how much one question is worth as tests get shorter. On a 10-question quiz each item carries 10 points, so two mistakes drop a student from an A to a B-; on a 50-question exam the same two mistakes cost 4 points and barely move the letter. Short quizzes are far harsher per error, which is worth remembering when you set the length. Averaging several tests together is the job of the grade average calculator.
Frequently asked questions
- How do I grade a test by number wrong?
- Subtract the number wrong from the total questions, divide by the total, and multiply by 100. 22 correct out of 25 is 88%.
- What is an EZ grader?
- A quick tool that converts the number of questions and the number missed into a percentage score — exactly what this calculator does.
- What if questions have different point values?
- Use the grade percentage calculator with total points earned and total points possible instead.
- How much is each question worth?
- Each question is worth 100 ÷ number of questions percent. On a 20-question test that's 5% each.
- How many can I get wrong and still pass?
- Multiply the question count by the passing percentage and round up to get the number correct you need. On a 40-question test with a 70% pass mark you need 28 correct, so 12 wrong is the limit.