Test Grade Calculator
Number wrong → percentage and letter grade, with a printable chart for the whole test.
Grading chart
About the Test Grade Calculator
For marking a stack of tests: type how many questions (or points) the test has and how many a student got wrong — or right — and the percentage and letter grade appear at once. Underneath, a grading chart lists every possible number wrong with its percentage and letter, split into columns and ready to print and keep beside the marking pile.
Half- and quarter-point steps cover partial credit, you choose how percentages are rounded, and the grading scale — A–F 90/80/70/60 by default — can be switched to plus/minus bands or edited to your school’s own cut-offs. Nothing is uploaded: no student data leaves your browser.
How to use it
- Choose Questions or Points, then type the number of questions (or the total points).
- Pick Number wrong or Number right and type the student’s count — the percentage and letter update as you type.
- For partial credit, set Chart steps to half or quarter points; choose how to round the percentages (whole numbers by default).
- Check the grading scale and edit it if your school uses other cut-offs.
- Use Print chart for a paper copy (only the chart is printed), or download it as CSV for a spreadsheet.
Examples
22 ÷ 25 = 88% — B on the 90/80/70/60 scale (B+ on the plus/minus scale)
The chart shows that an A allows up to 2 wrong, a B up to 5, a C up to 7 and a D up to 10.
29 ÷ 30 = 96.666…% — shown as 97%, 96.7% or 96.67% depending on the rounding you pick
18.5 ÷ 20 = 92.5% — 93% rounded to whole numbers
29 questions, 3 wrong
26 ÷ 29 = 89.66%: 90% and an A when rounded to whole numbers, 89.7% and a B at one decimal
How the percentage is worked out
percentage = (total − number wrong) ÷ total × 100
With 25 questions and 3 wrong: (25 − 3) ÷ 25 × 100 = 88%. In points mode the same formula uses points: 1.5 points lost on a 20-point quiz gives 18.5 ÷ 20 = 92.5%.
Percentages are rounded half up to the number of decimals you choose (whole numbers by default), and the letter is read from the rounded percentage — so the letter always matches the number you write on the paper. If your school decides letters from unrounded scores, choose two decimals.
Using the chart
The chart lists every possible number wrong from 0 to the full test, in steps of 1, 0.5 or 0.25. A line marks where the letter grade changes, the student you just typed is highlighted, and the note under the chart says how many wrong each letter allows.
Print chart prints only the chart (four columns per page, with the test size, rounding and scale above it). The chart can have up to 2,001 rows — for example 500 points in quarter steps.
Limitations
- Every question counts the same in Questions mode. For tests with different point values per question, use Points mode with the total points.
- Curves, bonus questions and minimum-score policies are not applied — add bonus points to the total yourself if your school counts them that way.
- Up to 1,000 questions or points.
Privacy
Everything happens in your browser: test sizes, scores and your grading scale are never uploaded. The scale you set is remembered only in this browser.
Frequently asked questions
How do I work out a test percentage from the number wrong?
Subtract the number wrong from the number of questions, divide by the number of questions and multiply by 100. 3 wrong out of 25 is 22 ÷ 25 × 100 = 88%.
How many questions can a student miss and still get an A?
Look at the chart or the note under it: on a 25-question test with A at 90%, up to 2 wrong is still an A (92%), while 3 wrong is 88%.
How do I grade half points?
Set Chart steps to half points. You can type 2.5 wrong (or switch to Points and type points lost); the chart then lists 0, 0.5, 1, 1.5 … wrong.
Why did the letter change when I changed the rounding?
Letters follow the rounded percentage. 89.66% rounds to 90% (an A on a 90% cut-off) as a whole number but stays 89.7% (a B) at one decimal. Pick the rounding your school uses.
Can I use my school’s grading scale?
Yes. Open Grading scale, start from one of the presets and change the lowest percentage for each letter, or add and remove letters. It is remembered in this browser and also used by the grade calculator and the final grade calculator.