How 60 out of 60 works out to 100%
Divide the score by the total and multiply by a hundred: 60 ÷ 60 × 100 = 100%. Each of the 60 questions is worth 1.67%, so the grade can only land on multiples of 1.67% — there is no way to score 99.2% on a sixty-question test.
Nothing was wrong: this is full marks, 60 out of 60.
100% as a letter grade
Schools do not all cut letters at the same percentage, so 100% has more than one correct answer. Here is where it lands on the three scales in common US use:
| Scale | Where 100% lands | Grade points |
|---|---|---|
| Plus/minus, the most common US scale | A+ | 4.00 |
| Straight letters, 90/80/70/60 | A | 4.00 |
| Seven-point, 93/85/77/70 | A | 4.00 |
On the plus/minus scale this site uses throughout, 60 out of 60 is an A+, worth 4.00 grade points on an unweighted 4.0 scale. A school that grades in straight letters, with no pluses or minuses, would record the same score as an A. A seven-point scale reads it as an A as well. The full band table for all three, and what each letter is worth on the 4.0, 4.3 and 5.0 scales, is on letter grade to GPA.
If this grade came from a weighted class the grade points move rather than the letter: 4.00 becomes 4.50 in an honors class and 5.00 in an AP or IB class, on the usual +0.5 and +1.0 bumps. The high school GPA calculator applies those automatically.
There is nothing above this
60 out of 60 is full marks and the top of the scale: 100%, an A+, 4.00 grade points. The nearest score below it is 59 out of 60, which is 98.3% — an A+. On a sixty-question test one wrong answer costs 1.67%, which is not enough to change the letter.
The scores either side of 60 out of 60
One fewer is 59 out of 60, 98.3% — still an A+. Nothing exists in between. A sixty-question test has exactly 60 achievable grades above zero and 100% is one of them; a percentage that is not a multiple of 1.67% cannot come off a test this length, whatever a rounding rule does to it afterwards.
What 100% does to a course average
One test is rarely the whole grade. If everything else in the course is averaging 85% and this test is worth the share in the left-hand column, the course grade lands here:
| Test is worth | Course grade | Letter |
|---|---|---|
| 10% of the course | 86.5% | B |
| 20% of the course | 88% | B+ |
| 30% of the course | 89.5% | B+ |
| 40% of the course | 91% | A- |
Because 100% is above that 85% baseline, this test pulls the course average up by 3 points at a 20% weighting. Weightings vary, and a syllabus that puts the final at 30% is a different problem from one that puts it at 10% — put your own categories into the grade calculator, or work backwards from the grade you need with the final grade calculator.
100% on other test lengths
100% is not unique to a sixty-question test. The same percentage comes out of 10 out of 10, 20 out of 20, 25 out of 25, 30 out of 30, 40 out of 40, 50 out of 50 and 100 out of 100. The letter grade is identical on all of them, because the letter only ever looks at the percentage. What differs is the granularity: 60 out of 60 moves in steps of 1.67%, while 100 out of 100 moves in steps of 1%, so the longer test can express grades the shorter one simply cannot reach.
About sixty-question tests
A sixty-question test, usually a final, a practice standardised paper or a two-period exam. Every score on one, from 1 to 60, is charted on the out of 60 page, and the easy grader turns the same table around for marking a stack of papers: count what is wrong rather than what is right.