Percentage Calculator · Practical guide
How to Calculate Your Test Score Percentage
Points earned ÷ total points × 100 — plus a lookup table for common scores and letter grades.
At a glance
The Test Score Formula
To calculate a test score percentage, divide the points you earned by the total points possible, then multiply by 100:
Score % = (Points Earned ÷ Total Points) × 100
Scoring 42 out of 50 gives (42 ÷ 50) × 100 = 84%. If every question is worth the same amount, you can count questions instead: 36 right out of 40 is (36 ÷ 40) × 100 = 90%.
Interactive tool
Percentage Calculator
Enter your own values, then compare the result with the examples below.
Score Table: Out of 50 Points
| Points Earned | Percentage | Typical Letter Grade |
|---|---|---|
| 35 | 70% | C− |
| 38 | 76% | C |
| 40 | 80% | B− |
| 42 | 84% | B |
| 45 | 90% | A− |
| 47 | 94% | A |
Letter grade cutoffs vary by school, but a common scale is 90–100% = A, 80–89% = B, 70–79% = C, 60–69% = D, and below 60% = F.
How Many Questions Can You Miss?
Work backward from your target. To hold an A− (90%) on a 50-question test, you need at least 0.9 × 50 = 45 correct, so you can miss at most 5. On a 25-question quiz, 90% requires 22.5 — since half-points rarely exist, you need 23 right and can miss only 2. Shorter tests give you less room for error: each missed question on a 10-question quiz costs a full 10 percentage points.
Frequently Asked Questions
What is 42 out of 50 as a percentage?
(42 ÷ 50) × 100 = 84%. On a typical grading scale, that is a B.
How many questions can I miss and still get an A?
On a 50-question test you need at least 45 correct (90%), so you can miss 5. On a 20-question test, missing more than 2 drops you below an A−.
What if some questions are worth more points?
Add up the actual points you earned and divide by the total points available. Question count only works when every question carries equal weight.
Can a test score be over 100%?
Yes, with bonus or extra-credit points. Earning 53 points out of 50 possible gives (53 ÷ 50) × 100 = 106%.