Test Grade Calculator
How many questions can you miss? Enter your test size and mistakes to see your percentage and letter grade instantly.
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How Test Grades Are Calculated
or equivalently
Score = ((Total Questions − Questions Wrong) / Total Questions) × 100%
Example: On a 40-question test, you answer 34 correctly (6 wrong):
Score = (34 / 40) × 100 = 0.85 × 100 = 85% (B grade)
The letter grade cutoffs shown in this calculator follow the standard US grading scale: A (90–100%), B (80–89%), C (70–79%), D (60–69%), F (below 60%). However, grading scales vary by school and instructor, so check your syllabus for the exact thresholds used in your class.
Quick Reference: Common Test Sizes
Use these tables to quickly find your grade without a calculator.
10-Question Test
| Wrong | % | Grade |
|---|---|---|
| 0 | 100 | A |
| 1 | 90 | A |
| 2 | 80 | B |
| 3 | 70 | C |
| 4 | 60 | D |
| 5+ | <50 | F |
20-Question Test
| Wrong | % | Grade |
|---|---|---|
| 0–1 | 95–100 | A |
| 2–3 | 85–90 | B |
| 4–6 | 70–80 | C |
| 7–8 | 60–65 | D |
| 9+ | <55 | F |
25-Question Test
| Wrong | % | Grade |
|---|---|---|
| 0–2 | 92–100 | A |
| 3–5 | 80–88 | B |
| 6–8 | 68–76 | C |
| 9–10 | 60–64 | D |
| 11+ | <56 | F |
50-Question Test
| Wrong | % | Grade |
|---|---|---|
| 0–5 | 90–100 | A |
| 6–10 | 80–88 | B |
| 11–15 | 70–78 | C |
| 16–20 | 60–68 | D |
| 21+ | <58 | F |
100-Question Test
| Wrong | % | Grade |
|---|---|---|
| 0–10 | 90–100 | A |
| 11–20 | 80–89 | B |
| 21–30 | 70–79 | C |
| 31–40 | 60–69 | D |
| 41+ | <59 | F |
Frequently Asked Questions
How many questions can I miss and still get an A?
To get an A (90% or higher), you can miss up to 10% of the questions. On a 40-question test, that's 4 questions. On a 100-question test, 10 questions. Use the wrong-answer chart above to find the exact number for your test size.
Can I use this for partial credit tests?
Yes! Use the "Partial Credit" mode to enter each question and how many points you earned on it. The calculator will show your total score and grade. For simple tests, the "Points Earned" mode is faster.
Do all schools use the same grading scale?
No. Most US schools use 90–100% = A, 80–89% = B, etc., but some use different cutoffs (like 93% for A or weighted scales). Always check your syllabus or ask your instructor to confirm their grading scale. This calculator uses the standard scale as a default.
What if my score is above 100%?
This can happen with extra credit points or a curve. The calculator will show your score above 100% and your letter grade accordingly. Check with your instructor on how scores over 100% are handled—some cap it, others award the A automatically.
Is my data saved?
Everything stays in your browser—nothing is uploaded to any server. Your inputs are not saved between sessions unless your browser cache persists them.
What grade scale does this use?
The default is the standard US scale: A (90–100%), B (80–89%), C (70–79%), D (60–69%), F (below 60%). You can edit the cutoff percentages if your school uses a different scale.
Sources
- Academic Grading in the United States — Wikipedia
- Grade Calculator — Calculator.net
- Final Grade Calculator — RogerHub
Grading scale note: This calculator uses the most common US standard (A: 90–100%, B: 80–89%, C: 70–79%, D: 60–69%, F: <60%). However, grading scales vary significantly by school, district, and instructor. The scale shown here is a default reference, not an official conversion. Always verify with your course syllabus.