What is 18 out of 20 as a Grade?
18 out of 20 is 90% — an A- letter grade.
If you scored 18 correct answers on a 20-question test, you answered 90% of the questions correctly and missed 2. Under the standard grading scale used by most U.S. schools and colleges, 90% falls in the A- range, which is an excellent score reflecting strong academic performance.
| Score | Percentage | Letter Grade |
|---|---|---|
| 18 out of 20 | 90% | A- |
How Is 18/20 Calculated?
18 ÷ 20 × 100 = 90%
You divide your score (18) by the total questions (20), then multiply by 100 to get your percentage. A 90% places you in the A- range on the standard academic grading scale.
What Letter Grade Is 18 out of 20?
Under the standard U.S. grading scale, 18 out of 20 is an A- grade (90%).
| Percentage Range | Letter Grade |
|---|---|
| 97% – 100% | A+ |
| 93% – 96.99% | A |
| 90% – 92.99% | A- |
| 87% – 89.99% | B+ |
| 83% – 86.99% | B |
| 80% – 82.99% | B- |
| 77% – 79.99% | C+ |
| 73% – 76.99% | C |
| 70% – 72.99% | C- |
| 60% – 69.99% | D |
| 0% – 59.99% | F |
At exactly 90%, an 18/20 score sits right at the bottom threshold of the A- range. It is just 3% away from a full A (93%), which would require scoring 19 out of 20 (95%).
Complete 20-Question Test Grading Scale
Scored on a 20-question test? Here is every possible score with its percentage and letter grade:
| Correct Answers | Wrong Answers | Percentage | Letter Grade |
|---|---|---|---|
| 20 | 0 | 100% | A+ |
| 19 | 1 | 95% | A |
| 18 | 2 | 90% | A- |
| 17 | 3 | 85% | B |
| 16 | 4 | 80% | B- |
| 15 | 5 | 75% | C |
| 14 | 6 | 70% | C- |
| 13 | 7 | 65% | D |
| 12 | 8 | 60% | D |
| 11 | 9 | 55% | F |
| 10 | 10 | 50% | F |
Note: On a 20-question test, B+ (87–89.99%) and C+ (77–79.99%) are not achievable with whole number scoring. Each question is worth exactly 5%, so scores jump from 85% (B) directly to 90% (A-), and from 75% (C) directly to 80% (B-).
Is 18 out of 20 a Good Grade?
Yes — 18 out of 20 is an excellent grade.
For passing purposes: Absolutely. 90% is far above the typical passing threshold of 60–70% at most schools. You passed with a strong A-.
For GPA purposes: An A- grade (90%) corresponds to a 3.7 GPA on the standard 4.0 scale. This is a strong GPA contribution that reflects excellent academic performance in the course.
For competitive programs: Most competitive programs including pre-med, nursing, law, and engineering consider an A- to be a strong result. A 90% meets or exceeds the grade requirements of virtually all academic programs.
Bottom line: 18/20 is an excellent score. To reach a full A you would need 19 out of 20 (95%), and a perfect score requires all 20 correct (100%).
How Many Questions Can You Get Wrong on a 20-Question Test?
| Target Grade | Minimum Correct | Maximum Wrong |
|---|---|---|
| A+ (100%) | 20 | 0 |
| A (93%) | 19 | 1 |
| A- (90%) | 18 | 2 |
| B (83%) | 17 | 3 |
| B- (80%) | 16 | 4 |
| C (73%) | 15 | 5 |
| C- (70%) | 14 | 6 |
| D (60%) | 12 | 8 |
Note: B+ and C+ grades are not achievable on a 20-question test because each question is worth 5%, creating gaps between scores that skip those grade ranges entirely.
Calculate Your Own Grade Instantly
Need to calculate a different score? Use our free Grade Calculator to instantly find the percentage and letter grade for any test score — just enter the total number of questions and how many you got wrong.
👉 Use the Free Grade Calculator →
It supports custom grading scales, half points, bonus points, and works for tests of any length from 1 to 500 questions.
Frequently Asked Questions
What is 18 out of 20 as a percentage? 18 divided by 20 equals 0.90, which as a percentage is 90%. To calculate it: 18 ÷ 20 × 100 = 90%.
Is 18 out of 20 an A or A- grade? 18 out of 20 is an A- grade. It equals exactly 90%, which is the lowest score in the A- range (90–92.99%). To earn a full A you would need 19 out of 20, which equals 95%.
What GPA is 18 out of 20? An 18/20 score equals 90% (A-), which corresponds to a 3.7 GPA on the standard 4.0 scale.
How many wrong answers is 18 out of 20? If you scored 18 out of 20, you got 2 questions wrong. 20 total minus 18 correct equals 2 incorrect answers.
Is 90% a good grade? Yes. A 90% is an A- grade and is considered excellent academic performance. It is well above average and reflects strong understanding of the material. On a 4.0 GPA scale it contributes a 3.7, which is a strong score for any academic program.
What is 18/20 as a fraction in simplest form? 18/20 simplifies to 9/10. Divide both numerator and denominator by 2: 18 ÷ 2 = 9 and 20 ÷ 2 = 10.