How do you calculate a test grade percentage?

Test grade percentage = (Points scored / Total points) x 100. Examples: - 18/20: (18/20) x 100 = 90% (A-) - 45/50: (45/50) x 100 = 90% (A-) - 33/40: (33/40) x 100 = 82.5% (B) - 72/100: 72% (C+) - 7/10: 70% (C-) Common US letter grade thresholds: - A+: 97% and above - A: 93-96% - A-: 90-92% - B+: 87-89% - B: 83-86% - B-: 80-82% - C+: 77-79% - C: 73-76% - C-: 70-72% - D: 60-69% - F: below 60% Note: grade thresholds vary by institution and professor. Some courses use 90/80/70/60 as round cutoffs without plus/minus grades.

How does a grade curve work?

A grade curve adjusts scores upward to account for a test being too difficult. There are two common types: Points curve: the professor adds a fixed number of raw points to everyone's score before calculating the percentage. Example: score 33/40 with a 5-point curve becomes (33+5)/40 = 38/40 = 95% (A). Percent curve: the professor adds percentage points directly to the calculated grade. Example: 33/40 = 82.5%, plus a 5% curve = 87.5% (B+). Note that 82.5 + 5 = 87.5, not (33+5)/40 which would be 95% — these give different results. Other curve methods not covered here: - Square root curve: new score = sqrt(original score) x 10 (useful for 100-point tests) - Highest score curve: everyone gets bonus points equal to 100 minus the top score - Bell curve: grades are assigned based on class distribution percentiles Always confirm which method your professor is using before calculating.

How do I know what score I needed for a higher grade?

The score table shows the exact points needed for each letter grade given your total. It calculates: Points needed = (Target % / 100) x Total points. For a 40-point test: - A+ (97%): 38.8 points needed - A (93%): 37.2 points needed - A- (90%): 36.0 points needed - B+ (87%): 34.8 points needed - B (83%): 33.2 points needed (scoring 33 gives exactly B) If a curve applies, the table adjusts accordingly. For a 5-point curve on a 40-point test, you need (34.8 - 5) = 29.8 points raw to get a B+ after curving. The status column shows a tick for grades you have already achieved (green), an arrow for your current grade (white on black), and a cross for grades that required more than the total points available.

What is the difference between a grade percentage and a grade point (GPA)?

A grade percentage is the raw score expressed as a proportion of total points (e.g. 82.5%). A grade point is a number on the 4.0 scale used to calculate GPA (e.g. 3.0 for a B). The mapping between them: - A+ (97-100%) = 4.0 GPA points - A (93-96%) = 4.0 GPA points - A- (90-92%) = 3.7 - B+ (87-89%) = 3.3 - B (83-86%) = 3.0 - B- (80-82%) = 2.7 - C+ (77-79%) = 2.3 - C (73-76%) = 2.0 - C- (70-72%) = 1.7 - D (60-69%) = 1.0 - F (below 60%) = 0.0 GPA is then the weighted average of grade points across all courses, weighted by credit hours. A single test grade is one component of a course grade; the course grade determines the GPA contribution.

Does it matter if my test is out of 20, 50, or 100 points?

The total points do not affect the letter grade — only the percentage matters. A 90% is an A- whether you scored 18/20, 45/50, 90/100, or 9/10. However, the total does affect how much each question is worth and how sensitive the grade is to small errors: On a 20-point test: each point = 5 percentage points. Missing one question drops you from 100% to 95% — a full grade band jump. On a 100-point test: each point = 1 percentage point. Missing one question drops you from 100% to 99% — barely noticeable. On a 50-point test: each point = 2 percentage points. Missing 5 questions drops from 100% to 90% — one full letter grade. This is why professors often give higher-stakes tests more total points — it smooths out the grade distribution and makes each question worth less as a percentage. The score table on this calculator automatically shows the exact points needed per grade regardless of your total.

Test Grade Calculator — Score to Percentage and Letter Grade

The Test Grade Calculator converts any raw test score to a percentage and letter grade instantly. Enter points scored and total points — the grade, letter, and GPA equivalent appear immediately with a colour-coded half-circle dial. Add a curve as extra points or extra percentage ...

YOUR SCORE

SCORE

Points scored

Total points

CURVE (OPTIONAL)

YOUR GRADE

A−

90%

Score

18/20

GPA: 3.7

RAW %

90%

DROPPED

2 pts

LETTER

A−

SCORES NEEDED FOR EACH GRADE (out of 20)

Grade	Min %	Points Needed	Status
A+	97%	19.4	—
A	93%	18.6	—
A−	90%	18	← You
B+	87%	17.4	✓
B	83%	16.6	✓
B−	80%	16	✓
C+	77%	15.4	✓
C	73%	14.6	✓
C−	70%	14	✓
D+	67%	13.4	✓
D	63%	12.6	✓
D−	60%	12	✓
F	0%	0	✓

QUICK EXAMPLES

GRADE DIAL

LETTER GRADE SCALE

A+≥97%4.0

A≥93%4.0

A−≥90%3.7

B+≥87%3.3

B≥83%3.0

B−≥80%2.7

C+≥77%2.3

C≥73%2.0

C−≥70%1.7

D+≥67%1.3

D≥63%1.0

D−≥60%0.7

F≥0%0.0

Questions right (if 1pt each)

18 / 20

Points dropped

2 pts

GPA equivalent

3.7

Ratio

18 : 20

Created with❤️byeaglecalculator.com

HOW TO USE

1
Enter your points scored in the left box and total points possible in the right box. The score appears as a large fraction (e.g. 18/20) so you can verify you entered it correctly.
2
If your professor is applying a curve, select the curve type: Points (extra points added to your raw score) or Percent (percentage points added to your grade). Enter the curve amount. Leave it on No Curve if there is none.
3
Your letter grade and percentage appear instantly in the hero box, colour-coded by grade range. The grade dial on the right shows your position on the 0-100% arc.
4
The score table shows exactly how many points out of the total you would need for every grade from A+ down to F — useful for knowing how close you were to the next grade up.
5
Use the quick example buttons to try different scores including curved examples, or click Share to copy your result.

WORKED EXAMPLE

18/20: (18/20)x100=90% (A-). Dropped 2 pts. 33/40: 82.5% (B). With +5pt curve: (33+5)/40=95% (A). With +5% curve: 82.5+5=87.5% (B+). Points needed for A- on 40pt test: 0.90x40=36 pts. 72/100: 72% (C+). GPA equivalent: 2.3.

FORMULAS

TEST GRADE FORMULAS

NAME	FORMULA	DESCRIPTION
Percentage grade	Grade % = (Score / Total) x 100	Convert raw score to percentage
Points curve	Curved % = ((Score + Curve pts) / Total) x 100	Add extra points to raw score before converting
Percent curve	Curved % = (Score / Total x 100) + Curve %	Add percentage points directly to the grade
Points needed for grade	Points = (Target % / 100) x Total	Minimum score needed for a given letter grade
Points dropped	Dropped = Total - Score	How many points were lost

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Last updated: April 29, 2026 · Formula verified by EagleCalculator team · Eagle-eyed accuracy for every calculation.