12 out of 21 as a percentage is 57.14% (F)

A 12/21 is 57.14%, which is an F on the standard grading scale. That is a 0.0 GPA, and you got 9 wrong.

Next grade1 more → D13 out of 21 is 61.9%

With a 5-point curve62.14% → Dif your teacher adds 5 points

To pass (60%)1 more needed13 out of 21 is the passing line

What a 12/21 grade means

12 correct and 9 wrong on a 21-question test.
Each question is worth 4.76%, so every wrong answer costs 4.76 percentage points.
Any score from 0 to 12 out of 21 is an F.
1 more correct (13 out of 21, 61.9%) would make it a D.
It is below a 60% passing score, which needs 13 out of 21: 1 more correct.

Divide the score by the total: 12 ÷ 21 = 0.5714.
Multiply by 100: 0.5714 × 100 = 57.14%.
Find 57.14% 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 57%, 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 21, with 12 highlighted. Pick any score to see its page.

Correct	Wrong	Percentage	Grade
21	0	100%	A
20	1	95.2%	A
19	2	90.5%	A
18	3	85.7%	B
17	4	81%	B
16	5	76.2%	C
15	6	71.4%	C
14	7	66.7%	D
13	8	61.9%	D
12	9	57.1%	F
11	10	52.4%	F
10	11	47.6%	F
9	12	42.9%	F
8	13	38.1%	F
7	14	33.3%	F
6	15	28.6%	F
5	16	23.8%	F
4	17	19%	F
3	18	14.3%	F
2	19	9.5%	F
1	20	4.8%	F
0	21	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, 12.5 out of 21 is 59.52%: an F on the standard scale and an F with plus and minus grades.

8 at most with a 60% passing score: you need 13 out of 21. With a 70% passing score you need 15 out of 21.