6 out of 18 as a percentage is 33.33% (F)

A 6/18 is 33.33%, which is an F on the standard grading scale. That is a 0.0 GPA, and you got 12 wrong.

Next grade5 more → D11 out of 18 is 61.11%

With a 5-point curve38.33% → Fif your teacher adds 5 points

To pass (60%)5 more needed11 out of 18 is the passing line

What a 6/18 grade means

6 correct and 12 wrong on a 18-question test.
Each question is worth 5.56%, so every wrong answer costs 5.56 percentage points.
Any score from 0 to 10 out of 18 is an F.
5 more correct (11 out of 18, 61.11%) would make it a D.
It is below a 60% passing score, which needs 11 out of 18: 5 more correct.

Divide the score by the total: 6 ÷ 18 = 0.3333.
Multiply by 100: 0.3333 × 100 = 33.33%.
Find 33.33% on the grading scale: A is 90% and up, B 80%, C 70% and D 60%, so it is an F.

Rounded to a whole number this is 33%, and the letter grade stays the same.

Scale	Cutoffs	Letter
Standard A–F	A 90, B 80, C 70, D 60	F
Plus and minus	A 93, A− 90, B+ 87, B 83, B− 80 …	F
7-point	A 93, B 85, C 77, D 70	F

Which scale applies depends on your school or teacher; the syllabus usually says. The grading scales guide compares them.

Every possible score out of 18, with 6 highlighted. Pick any score to see its page.

Correct	Wrong	Percentage	Grade
18	0	100%	A
17	1	94.4%	A
16	2	88.9%	B
15	3	83.3%	B
14	4	77.8%	C
13	5	72.2%	C
12	6	66.7%	D
11	7	61.1%	D
10	8	55.6%	F
9	9	50%	F
8	10	44.4%	F
7	11	38.9%	F
6	12	33.3%	F
5	13	27.8%	F
4	14	22.2%	F
3	15	16.7%	F
2	16	11.1%	F
1	17	5.6%	F
0	18	0%	F

No. Below 60% is an F, a failing grade on the standard US scale.

0.0 on a 4.0 scale, as an F.

With a half point, 6.5 out of 18 is 36.11%: an F on the standard scale and an F with plus and minus grades.

7 at most with a 60% passing score: you need 11 out of 18. With a 70% passing score you need 13 out of 18.