Test Grade Calculator

How to Calculate a Test Grade

A test grade is a simple fraction — questions correct over questions total — expressed as a percentage and, usually, a letter. This calculator is built for both sides of the desk: teachers grading a stack of quizzes who want to look up scores instead of re-dividing for every paper, and students who just got a test back marked “−6” and want to know what that means for their grade. Enter the total number of questions and the number wrong, and you get the percentage, the letter grade, and a full grading chart for every possible score on that test.

How to Use This Calculator

1. Enter the total number of questions on the test or quiz.
2. Enter the number of wrong answers. If you know the number correct instead, subtract it from the total first.
3. Read the score panel. It shows the percentage, the letter grade on the standard scale, and the score as a fraction.
4. Use the grading chart below the result. It lists every wrong-answer count for your test size with its percentage and letter — the classic grading-chart workflow. Grade the whole stack from one screen.

The Test Grade Formula

Score = (Total questions − Wrong answers) ÷ Total questions × 100

Worked example: a 30-question test with 6 wrong answers. First find the number correct: 30 − 6 = 24. Then divide: 24 ÷ 30 = 0.80. Multiply by 100 to get 80%. On the standard scale, 80-82% is a B-, so 24 out of 30 is an 80% B-. The same three steps work for any test where every question counts equally.

For Teachers: Grading a Stack Quickly

The grading chart is the fastest way to grade a pile of identical tests. Set the total once, and every paper becomes a single lookup: count the wrong answers, find that row, write the percentage. No re-typing, no division errors at paper number forty.

If you plan to curve, decide whether the curve comes before or after the letter. Curving up-front — for example, dropping a bad question and grading out of 29 instead of 30 — just means changing the total in the calculator and reading the new chart. Curving after the fact — adding points to every raw score, or scaling to the top score in the class — happens outside this tool: compute raw percentages first, then apply the adjustment consistently to everyone. Mixing the two (dropping a question for some students and adding points for others) is where grading disputes come from.

Partial Credit and Weighted Questions

This calculator assumes every question is worth the same and is scored entirely right or wrong. Many real tests are not built that way: an exam might have 40 multiple-choice questions worth 1 point each and 2 essays worth 30 points each. For those, the fraction that matters is points earned ÷ points possible, not questions right over questions total. The math is the same division — just done on points. If you are combining a test score with homework, quizzes, and a final into a course grade, the grade calculator handles weighted categories properly.

Limitations

This tool reports a raw equal-weight score and converts it with the common US grade bands. It cannot account for partial credit, weighted sections, penalty scoring for wrong guesses, curves, or your school's specific letter ranges. Treat the letter grade as the standard-scale default; the percentage itself is exact for any equal-weight test.