Free · No sign-up · Built for teachers
EZ Grader: grade a stack of tests in seconds
Enter the total number of questions on the test. The chart below instantly shows the grade for every possible number wrong — no sliding paper chart, no per-student math.
Where this comes from
What an EZ Grader actually replaces
Before digital tools, teachers used a physical sliding cardboard or plastic chart — line up the total number of questions on one edge, and a window would reveal the percentage for any number wrong. This tool does the same lookup instantly for any test length, without needing the physical chart on hand.
Common test lengths
How many wrong for a B on common test sizes
| Total Questions | Points per Question | Wrong answers for ~90% (A-) | Wrong answers for ~80% (B-) |
|---|---|---|---|
| 10 | 10.0% | 1 wrong | 2 wrong |
| 20 | 5.0% | 2 wrong | 4 wrong |
| 25 | 4.0% | 2–3 wrong | 5 wrong |
| 50 | 2.0% | 5 wrong | 10 wrong |
| 100 | 1.0% | 10 wrong | 20 wrong |
Shorter tests have less room for error — on a 10-question quiz, a single wrong answer already costs a full 10 points, while on a 100-question final the same single mistake costs just one point. This is why the same number of “wrong answers” means something very different depending on test length, and why a generic chart doesn’t work as well as one generated for your exact test.
FAQ
EZ Grader questions
What is an EZ Grader?
A reference chart — traditionally a sliding paper tool — showing the percentage grade for any number of questions missed on a test of a given length.
How many questions can I miss for a B on a 25-question test?
Each question is worth 4 points. Missing 3 keeps you at 88% (B+); missing 4 drops to 84% (B). Exact cutoffs vary by school.
Does this work for any test length?
Yes — enter any total from a 10-question quiz to a 200-question final and the chart recalculates automatically.
Can I use this for tests with different point values per question?
This chart assumes every question is worth equal value. For tests with mixed point values, use the main Grade Calculator in Points mode instead.