Scores Out of 21 as Percentages
Every possible score on a 21-question test or assignment, converted to a percentage and letter grade — from 0/21 (0%) all the way to 21/21 (100%). Below the chart you'll find how to do the conversion yourself, the key passing and A-grade thresholds out of 21, and answers to the most common questions.
How to Convert a Score Out of 21 to a Percentage
To convert any score out of 21 to a percentage, divide the score by 21 and multiply by 100:
percent = (score ÷ 21) × 100
example: (19 ÷ 21) × 100 = 90.5%
The resulting percentage is then mapped to a letter grade on the standard 10-point scale. The full table below has already done this for every score out of 21.
Common Scores Out of 21
The score you need out of 21 to hit each key percentage threshold:
- Passing (D, 60%) 13/21 (61.9%) D
- Half marks (50%) 10.5/21 (50%) F
- C grade (70%) 15/21 (71.4%) C
- B grade (80%) 17/21 (81%) B
- A grade (90%) 19/21 (90.5%) A
- Perfect (100%) 21/21 (100%) A
In short: you need 13/21 to pass (60%) and 19/21 for an A (90%).
Full Grade Chart — Every Score Out of 21
| Score | Percentage | Letter Grade | Wrong |
|---|---|---|---|
| 0/21 | 0% | F | 21 |
| 1/21 | 4.8% | F | 20 |
| 2/21 | 9.5% | F | 19 |
| 3/21 | 14.3% | F | 18 |
| 4/21 | 19% | F | 17 |
| 5/21 | 23.8% | F | 16 |
| 6/21 | 28.6% | F | 15 |
| 7/21 | 33.3% | F | 14 |
| 8/21 | 38.1% | F | 13 |
| 9/21 | 42.9% | F | 12 |
| 10/21 | 47.6% | F | 11 |
| 11/21 | 52.4% | F | 10 |
| 12/21 | 57.1% | F | 9 |
| 13/21 | 61.9% | D | 8 |
| 14/21 | 66.7% | D | 7 |
| 15/21 | 71.4% | C | 6 |
| 16/21 | 76.2% | C | 5 |
| 17/21 | 81% | B | 4 |
| 18/21 | 85.7% | B | 3 |
| 19/21 | 90.5% | A | 2 |
| 20/21 | 95.2% | A | 1 |
| 21/21 | 100% | A | 0 |
Letter Grade Breakdown
Letter grades out of 21 use the standard 10-point scale:
- A — 90% and above (19/21 or higher)
- B — 80% to 89.9% (17/21 or higher)
- C — 70% to 79.9% (15/21 or higher)
- D — 60% to 69.9% (13/21 or higher)
- F — below 60% (under 13/21)
Frequently Asked Questions
What is a passing score out of 21?
On the standard 10-point scale, 60% is the passing threshold (a D). Out of 21, that means you need at least 13 correct to pass — 13/21 works out to 61.9%. Anything below 13/21 falls under 60% and is a failing grade.
How many questions can you get wrong out of 21 and still pass?
You can miss up to 8 questions out of 21 and still pass. Getting 13/21 correct gives you 61.9% (a D, the lowest passing grade). Miss more than 8 and you drop below 60%.
How many can you get wrong out of 21 and still get an A?
To earn an A you need 90% or higher. Out of 21, that means at least 19 correct (19/21 = 90.5%), so you can afford to miss at most 2 questions.
What is half of 21 as a percentage?
Half of 21 is 10.5, and 10.5/21 is exactly 50%. Under the standard 10-point scale that is a failing grade (F), since 50% is below the 60% passing line.
Is a score out of 21 graded on a 10-point scale?
Most US schools use the standard 10-point scale regardless of the denominator: A is 90%+, B is 80%+, C is 70%+, D is 60%+, and anything below 60% is an F. A raw score out of 21 is first converted to a percentage — divide by 21 and multiply by 100 — then mapped to a letter. Your own school's cutoffs may differ, so check your syllabus.
Related Tools
- Test Grade Calculator — grade any 21-question test interactively; enter the number wrong and get your score plus a printable grading scale.
- Percent to Letter Grade converter — turn any percentage into its letter grade on the standard scale.
- GPA Calculator — roll individual course grades and credit hours into a weighted or unweighted GPA.