How 40 out of 60 works out to 66.7%
Divide the score by the total and multiply by a hundred: 40 ÷ 60 × 100 = 66.7%. 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 67.5% on a sixty-question test.
66.7% is rounded. 40 ÷ 60 does not terminate: the exact figure is 66.6667%, which we show to one decimal place like every other percentage on this site. If your school rounds to a whole number instead, this score is recorded as 67% — and where that crosses a letter boundary it is worth checking which convention the gradebook uses, because the rounding rule and not the marking decides the letter. Ours is set out on the methodology page.
In lowest terms 40 out of 60 is 2 out of 3 — the same fraction with 20 divided out of both halves. That is worth noticing when a score looks unfamiliar: 2 out of 3 is the shape most people can read at a glance.
20 questions were wrong out of 60, and together they cost 33.3%. If any of them were marked with partial credit the real figure is a little higher — the test grade calculator takes half marks.
66.7% as a letter grade
Schools do not all cut letters at the same percentage, so 66.7% has more than one correct answer. Here is where it lands on the three scales in common US use:
| Scale | Where 66.7% lands | Grade points |
|---|---|---|
| Plus/minus, the most common US scale | D | 1.00 |
| Straight letters, 90/80/70/60 | D | 1.00 |
| Seven-point, 93/85/77/70 | F | 0.00 |
On the plus/minus scale this site uses throughout, 40 out of 60 is a D, worth 1.00 grade points on an unweighted 4.0 scale. A school that grades in straight letters would record it as a D too. On a seven-point scale, where the bands are seven points wide instead of ten, it drops to an F — the same work, a different transcript. 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: 1.00 becomes 1.50 in an honors class and 2.00 in an AP or IB class, on the usual +0.5 and +1.0 bumps. The high school GPA calculator applies those automatically.
What it takes to reach a D+
The next letter up is a D+, which starts at 67%. On a sixty-question test that is 41 out of 60 — one more correct answer than you have. Going the other way, 38 out of 60 is the lowest score that still counts as a D, so you are 2 questions clear of dropping to a D-.
The scores either side of 40 out of 60
One more correct answer is 41 out of 60, 68.3% — a D+. One fewer is 39 out of 60, 65% — still a D. Nothing exists in between. A sixty-question test has exactly 60 achievable grades above zero and 66.7% 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 66.7% 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 | 83.2% | B |
| 20% of the course | 81.3% | B- |
| 30% of the course | 79.5% | C+ |
| 40% of the course | 77.7% | C+ |
Because 66.7% is below that 85% baseline, this test pulls the course average down by 3.7 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.
66.7% on other test lengths
66.7% is not unique to a sixty-question test. The same percentage comes out of 20 out of 30. The letter grade is identical on all of them, because the letter only ever looks at the percentage. What differs is the granularity: 40 out of 60 moves in steps of 1.67%, while 20 out of 30 moves in steps of 3.33%, 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.