Easy Grader

What this easy grader does

This easy grader builds a complete score chart for any test. Enter the number of questions and it lists every possible number of wrong answers with the percentage and letter grade that goes with it, ready to print and keep next to your marking pile. It also works as a quick lookup: type how many a student got wrong and the score appears straight away.

It handles tests of up to 1,000 questions or points, half and quarter points for partial credit, and two letter scales. Nothing is uploaded or stored on a server, so it’s safe to use with class results.

How to use the easy grader

1. Type the number of questions, or the total points if questions carry different weights.
2. Choose whole, half or quarter steps if you give partial credit.
3. Pick how many decimals you want and which letter scale your school uses.
4. Enter a number wrong to see a single score; that row is highlighted in the chart.
5. Press Print chart to print only the table, or Copy chart to paste it into a spreadsheet.

How the scores are calculated

Each row uses the same simple formula:

score % = (total − number wrong) ÷ total × 100

On a 20-question quiz, one wrong answer costs 5 percentage points, so 3 wrong is 17 ÷ 20 = 85%, a B. On a 45-question test each question is worth about 2.22 points, so 3 wrong gives 42 ÷ 45 = 93.3%. That’s why a fixed “minus five per mistake” rule only works for 20-question tests, and why a chart saves so much time.

Questions	Each wrong answer costs	3 wrong
10	10 points	70%
20	5 points	85%
25	4 points	88%
40	2.5 points	92.5%
50	2 points	94%

Partial credit with the easy grader

If you award half marks, switch the step to 0.5. The chart then includes rows such as 2.5 wrong, which is common on short-answer and maths tests where a correct method earns some credit. For tests where questions have different values, enter the total points instead of the number of questions and read “wrong” as “points lost”.

Letter scales

The US plus/minus scale puts an A at 93%, A− at 90%, B+ at 87% and so on down to F below 60%. The simple 10-point scale uses A 90%, B 80%, C 70% and D 60%. If your school uses different cut-offs, the percentage column is still correct; only the letter would change.

Related tools

Combine test scores into a course grade with the Grade Calculator, work out a semester average with the GPA Calculator, and handle one-off conversions with the Percentage Calculator. Our guide on how to grade a test covers partial credit, curving and fair rounding. For background on letter grading, see this overview of US academic grading.

Frequently asked questions

What is an easy grader?

It’s a chart, originally a sliding cardboard scale, that shows the percentage score for every possible number of wrong answers on a test. Teachers use it to mark quickly without calculating each paper.

How do I grade a test with 30 questions?

Each question is worth 3.33 points. Enter 30 in the easy grader and read the row: 3 wrong is 90%, 5 wrong is 83.3%, 9 wrong is 70%.

Can I use it for points instead of questions?

Yes. Enter the total points on the test and treat the “wrong” column as points lost. It works the same way.

Does the easy grader handle half points?

Yes. Set the step to half or quarter points and the chart adds those rows.

How do I print the grading chart?

Press Print chart. Only the table is printed, without the rest of the page, so it fits neatly on paper.

Should scores be rounded?

That’s a school policy. Many teachers show one decimal on the chart and round only the final course grade, which avoids rounding the same student up twice.