Turn questions wrong into a grade.

Subtract the number wrong from the total number of questions to get the number correct, then divide that by the total and multiply by 100. For a 20-question test with 3 wrong: (20 − 3) ÷ 20 × 100 = 85%. This calculator does that automatically — just enter the total and how many you missed.

This calculator uses the standard U.S. scale: 90–100 is an A, 80–89 is a B, 70–79 is a C, 60–69 is a D, and below 60 is an F, with plus and minus steps in between (for example, 97+ is an A+ and 60–62 is a D-). Your school may set slightly different cutoffs, so check your syllabus if you're right on a boundary.

Some teachers award partial credit — a wrong or blank answer still earns half a point rather than zero. Turning on "half points per question" adds 0.5 points for every missed question before computing your percentage, which raises your score. Leave it off for standard all-or-nothing grading.

Yes. The calculation is the same whether it's a quiz, homework set, worksheet, or exam — any assignment scored as a number of correct items out of a total. Enter the total number of items and how many were right or wrong to get the percentage and letter grade.

Yes. On a 20-question test each question is worth 5% (100 ÷ 20), so one wrong answer drops you to 95%. On a 50-question test each is worth 2%, so a single miss costs less. Fewer questions means each one carries more weight — which is why short quizzes can swing your grade sharply.