15 Out of 18 – Every Score Out of 18 as a Percentage

Every score out of 18

Score	Wrong	Percent	Letter, 90-80-70-60
18 out of 18	0	100%	A
17 out of 18	1	94.44%	A
16 out of 18	2	88.89%	B
15 out of 18	3	83.33%	B
14 out of 18	4	77.78%	C
13 out of 18	5	72.22%	C
12 out of 18	6	66.67%	D
11 out of 18	7	61.11%	D
10 out of 18	8	55.56%	F
9 out of 18	9	50%	F
8 out of 18	10	44.44%	F
7 out of 18	11	38.89%	F
6 out of 18	12	33.33%	F
5 out of 18	13	27.78%	F
4 out of 18	14	22.22%	F
3 out of 18	15	16.67%	F
2 out of 18	16	11.11%	F
1 out of 18	17	5.56%	F
0 out of 18	18	0%	F

The scores for each letter out of 18

Letter	Scores	Wrong
A	17 to 18	0 to 1
B	15 to 16	2 to 3
C	13 to 14	4 to 5
D	11 to 12	6 to 7
F	0 to 10	8 to 18

The 90-80-70-60 scale as one state writes it into law: Florida Statutes, section 1003.437, "Middle and high school grading system" (The 2026 Florida Statutes, read on 6 October 2026 at leg.state.fl.us). It gives each letter a range of whole percents and a grade point value. A school, a district or a teacher may use another scale, and theirs decides the grade.

How it works

Out of 18, each letter from A to D takes two scores, so the misses allowed are odd: 1 for an A, 3 for a B, 5 for a C, 7 for a D. One question is worth 5.56 points.

Read the full guide

Ninths: a shortcut for scores out of 18

Since 18 is twice 9, each pair of right answers is one ninth of the test, 11.11%. That makes 14 right 7 ninths, 77.78%, and 16 right 8 ninths, 88.89%. For 15, take a third of both numbers first: 15/18 is 5/6, and 5 ÷ 6 = 0.8333. Half points count too: 13.5 out of 18 is exactly 75%.

Questions and answers

What is a 15 out of 18?

15 out of 18 is 83.33%, a B on the 90-80-70-60 scale, with 3 wrong. To the nearest whole number, the 15 out of 18 percentage is 83%. The same share is 10 right out of 12, or 5 out of 6.

What is a 14 out of 18, and what is 13 out of 18?

14 out of 18 is 77.78% and 13 out of 18 is 72.22%. Both are a C, with 4 and 5 wrong. 14/18 reduces to 7/9, while 13/18 stays as it is, since 13 is prime.

What is 12 out of 18?

12 out of 18 is 66.67%, a D, and 12/18 reduces to 2/3. 11 out of 18 is 61.11%, also a D. 10 out of 18 is 55.56%, under the 60% where a D starts; whether a D passes is for your school to say.

What is a 16 out of 18, and what is a 17 out of 18?

16 out of 18 is 88.89%, a B: 2 wrong lands 1.11 points short of an A. 17 out of 18 is 94.44%, an A. The step between them is one question, and it crosses the 90% line.

What is 5 out of 18, or 7 out of 18?

5 out of 18 is 27.78% and 7 out of 18 is 38.89%. Both are an F. From 7 right, 4 more correct answers are needed for a D, because 11 right is the first whole score at 60% or above.