Grading Scale Calculator
Customize letter grade thresholds, generate printable assignment points charts, and calculate exam curves with flat add, highest score, and square root models.
1. Grading Scale Builder & Presets
Select an official preset or customize minimum percentage thresholds.
Active: 13 granular thresholds (A+, A, A-, B+, B, B-, etc.)
≥ 97%
≥ 93%
≥ 90%
≥ 87%
≥ 83%
≥ 80%
≥ 77%
≥ 73%
≥ 70%
≥ 67%
≥ 63%
≥ 60%
Below 60%
Instant Grade Lookup
Enter any percentage to look up its letter grade and 4.0 GPA point equivalent on your active scale.
2. Points-to-Letter Table Generator
Generate an assignment conversion chart for any maximum point total.
| Points Earned | Percentage | Letter Grade | GPA Equiv |
|---|---|---|---|
| 50 / 50 | 100% | A+ | 4.0 |
| 49 / 50 | 98% | A+ | 4.0 |
| 48 / 50 | 96% | A | 4.0 |
| 47 / 50 | 94% | A | 4.0 |
| 46 / 50 | 92% | A- | 3.7 |
| 45 / 50 | 90% | A- | 3.7 |
| 44 / 50 | 88% | B+ | 3.3 |
| 43 / 50 | 86% | B | 3.0 |
| 42 / 50 | 84% | B | 3.0 |
| 41 / 50 | 82% | B- | 2.7 |
| 40 / 50 | 80% | B- | 2.7 |
| 39 / 50 | 78% | C+ | 2.3 |
| 38 / 50 | 76% | C | 2.0 |
| 37 / 50 | 74% | C | 2.0 |
| 36 / 50 | 72% | C- | 1.7 |
| 35 / 50 | 70% | C- | 1.7 |
| 34 / 50 | 68% | D+ | 1.3 |
| 33 / 50 | 66% | D | 1.0 |
| 32 / 50 | 64% | D | 1.0 |
| 31 / 50 | 62% | D- | 0.7 |
| 30 / 50 | 60% | D- | 0.7 |
| 29 / 50 | 58% | F | 0.0 |
| 28 / 50 | 56% | F | 0.0 |
| 27 / 50 | 54% | F | 0.0 |
| 26 / 50 | 52% | F | 0.0 |
| 25 / 50 | 50% | F | 0.0 |
| 24 / 50 | 48% | F | 0.0 |
| 23 / 50 | 46% | F | 0.0 |
| 22 / 50 | 44% | F | 0.0 |
| 21 / 50 | 42% | F | 0.0 |
| 20 / 50 | 40% | F | 0.0 |
| 19 / 50 | 38% | F | 0.0 |
| 18 / 50 | 36% | F | 0.0 |
| 17 / 50 | 34% | F | 0.0 |
| 16 / 50 | 32% | F | 0.0 |
| 15 / 50 | 30% | F | 0.0 |
| 14 / 50 | 28% | F | 0.0 |
| 13 / 50 | 26% | F | 0.0 |
| 12 / 50 | 24% | F | 0.0 |
| 11 / 50 | 22% | F | 0.0 |
| 10 / 50 | 20% | F | 0.0 |
| 9 / 50 | 18% | F | 0.0 |
| 8 / 50 | 16% | F | 0.0 |
| 7 / 50 | 14% | F | 0.0 |
| 6 / 50 | 12% | F | 0.0 |
| 5 / 50 | 10% | F | 0.0 |
| 4 / 50 | 8% | F | 0.0 |
| 3 / 50 | 6% | F | 0.0 |
| 2 / 50 | 4% | F | 0.0 |
| 1 / 50 | 2% | F | 0.0 |
| 0 / 50 | 0% | F | 0.0 |
3. Grade Curve Calculator
Curve an exam using Flat Add, Highest Score (100%), or Square Root.
| Original | Curved | Grade | Curved Grade |
|---|---|---|---|
| 68% | 73% | D+ | C |
| 72% | 77% | C- | C+ |
| 75% | 80% | C | B- |
| 81% | 86% | B- | B |
| 84% | 89% | B | B+ |
| 88% | 93% | B+ | A |
| 90% | 95% | A- | A |
| 92% | 97% | A- | A+ |
| 95% | 100% | A | A+ |
| 98% | 100% | A+ | A+ |
What Is a Grading Scale
A grading scale is a standardized academic framework that translates numerical scores and percentages into discrete letter grades and grade point averages (GPA). It establishes clear performance benchmarks for evaluating student mastery across assignments, examinations, and full courses.
Establish Minimum Cutoffs
Define descending percentage thresholds for each grade level, such as requiring 93% for an A, 83% for a B, and 73% for a C.
Score Student Work
Compute raw percentages by dividing total points earned by points possible: (Points ÷ Total) × 100.
Assign Letter & GPA
Assign the letter grade corresponding to the highest threshold met or exceeded, along with standard quality points on a 4.0 scale.
Standard Grading Scale Chart
The standard North American collegiate grading scale uses 13 distinct letter grade bands with associated 4.0 GPA quality points. Below is the complete conversion matrix:
| Letter Grade | Percentage Range | 4.0 Scale GPA | Performance Level |
|---|---|---|---|
| A+ | 97.0% – 100.0% | 4.0 (or 4.3) | Exceptional Mastery |
| A | 93.0% – 96.9% | 4.00 | Superior Achievement |
| A- | 90.0% – 92.9% | 3.70 | Excellent Standing |
| B+ | 87.0% – 89.9% | 3.30 | Very Good / Commendable |
| B | 83.0% – 86.9% | 3.00 | Above Average |
| B- | 80.0% – 82.9% | 2.70 | Good Standing |
| C+ | 77.0% – 79.9% | 2.30 | Competent / Satisfactory |
| C | 73.0% – 76.9% | 2.00 | Average Performance |
| C- | 70.0% – 72.9% | 1.70 | Minimum Major Requirement |
| D+ | 67.0% – 69.9% | 1.30 | Below Average / Passing |
| D | 63.0% – 66.9% | 1.00 | Bare Minimum Passing |
| D- | 60.0% – 62.9% | 0.70 | Lowest Passing Grade |
| F | Below 60.0% | 0.00 | Failing / No Credit |
10-Point vs 7-Point Grading Scales
While the 10-point scale divides grades into even 10% blocks, the traditional 7-point scale requires a 93% minimum for an A and sets 70% as the failing threshold. A direct comparison demonstrates how letter designations shift between both systems:
| Letter Grade | Standard 10-Point Scale | Strict 7-Point Scale | Threshold Difference |
|---|---|---|---|
| A | 90.0% – 100.0% | 93.0% – 100.0% | +3.0% higher cutoff |
| B | 80.0% – 89.9% | 85.0% – 92.9% | +5.0% higher cutoff |
| C | 70.0% – 79.9% | 77.0% – 84.9% | +7.0% higher cutoff |
| D | 60.0% – 69.9% | 70.0% – 76.9% | +10.0% higher cutoff |
| F (Fail) | Below 60.0% | Below 70.0% | Any score < 70% fails |
How to Convert Points to a Letter Grade
To convert raw points on an assignment into a letter grade, divide points scored by total possible points, multiply by 100 to find the percentage, and look up the matching band on your active scale. Consider a 50-point midterm exam example:
Worked Example: 50-Point Midterm Exam
| Points Earned (out of 50) | Percentage | Standard Letter Grade | 4.0 GPA |
|---|---|---|---|
| 47.0 – 50.0 pts | 94.0% – 100.0% | A | 4.0 |
| 45.0 – 46.5 pts | 90.0% – 93.0% | A- | 3.7 |
| 43.5 – 44.5 pts | 87.0% – 89.0% | B+ (Target Score) | 3.3 |
| 40.0 – 43.0 pts | 80.0% – 86.0% | B / B- | 3.0 / 2.7 |
| 35.0 – 39.5 pts | 70.0% – 79.0% | C+ / C / C- | 2.3 – 1.7 |
How Grade Curving Works
Grade curving adjusts student test scores to account for exam difficulty, normalize class distributions, and ensure equitable grading across course sections. The three most common mathematical curving techniques include:
1. Flat Point Addition (+N Points)
Uniform ShiftFormula: Curved Score = min(100, Raw Score + N). Every student receives the exact same point bonus regardless of baseline performance.
Worked Example: If an instructor adds +6 points to a challenging quiz, a 64% (D) becomes a 70% (C-), and an 88% (B+) becomes a 94% (A).
2. Highest Score Curve (Top Score = 100%)
Proportional ScalingFormula: Curved Score = (Raw Score ÷ Top Class Score) × 100. The highest score achieved in the class is elevated to 100%, and all other scores scale up proportionally.
Worked Example: If the highest score on an exam is 85%, a student with 68% receives (68 ÷ 85) × 100 = 80.0% (B-).
3. Square Root Curve (Concave Progression)
Progressive ReliefFormula: Curved Score = √(Raw Score) × 10. This nonlinear mathematical function provides larger point increases to lower raw scores while preserving upper ceiling boundaries.
Worked Example: A raw score of 49% becomes √49 × 10 = 70.0% (C-) (+21 pts boost), while an 81% becomes √81 × 10 = 90.0% (A-) (+9 pts boost).
How to Build a Custom Grading Scale
Building a custom grading scale requires establishing clear learning outcomes, setting realistic cutoff percentages, and publishing the scale in your course syllabus prior to the first assignment. Follow these pedagogical best practices:
- 1. Decide on Plus/Minus Granularity: Plus/minus grading rewards fine distinctions in student work (e.g. distinguishing an 89% high B+ from an 81% B-), whereas 5-tier scales (A, B, C, D, F) simplify gradebook management.
- 2. Verify Descending Integrity: Ensure each higher letter grade requires a strictly greater minimum percentage than the grade below it to prevent classification overlaps or ambiguous scoring bands.
- 3. Define Policy on Rounding: Explicitly communicate whether percentages round to whole numbers (e.g., 89.5% rounding up to 90.0% A-) or truncate strictly at the decimal point.
- 4. Align with Institutional Baselines: Check departmental requirements to confirm whether prerequisite courses mandate a minimum 70% or 73% threshold to earn credit for sequential enrollment.
What Is a Passing Grade
A passing grade is the minimum academic evaluation required to earn institutional course credit, which generally starts at a D (60.0%) for general electives but increases to a C (70.0% to 73.0%) for core prerequisites and graduate studies.
Earning a D- or D (60.0%–69.9%) yields course credit toward general graduation credit count but delivers only 0.7 to 1.3 GPA quality points.
Most STEM, healthcare, and engineering faculties require at least a C or C- (70.0%+) to advance to sequential course levels.
Graduate schools typically enforce a minimum B (80.0% / 3.0 GPA) average, treating C grades as unsatisfactory for degree conferral.
Under binary Pass/Fail grading, students earning 60% (or 70% depending on department) receive credit without impacting cumulative GPA calculations.
Related Grade Calculators
Grade Percentage Calculator
Convert raw point totals into exact percentage grades, letter grades, and GPA conversions with custom rounding.
GPA Calculator
Calculate semester GPA, cumulative college standing, weighted high school AP/IB scores, and future target planning.
Test Grade Calculator
Quickly score quizzes and exams from total questions and wrong answers with an ez-grader chart.
Weighted Grade Calculator
Calculate overall course grades when homework, tests, quizzes, and exams have distinct percentage weights.
Final Grade Calculator
Find out exactly what score you need on your final exam to secure your desired course letter grade.
Gradebook Calculator
Manage multiple course assignments, drops, and semester weights in a full digital gradebook.
Frequently Asked Questions
What is a 10-point grading scale?
A 10-point grading scale divides letter grades into uniform 10-percentage-point increments: 90% to 100% is an A, 80% to 89% is a B, 70% to 79% is a C, 60% to 69% is a D, and anything below 60% is an F.
What letter grade is 87 percent?
On a standard US plus/minus grading scale, 87% corresponds to a B+ (earning 3.3 grade points on a 4.0 GPA scale). On a simple 10-point scale without plus/minus distinctions, 87% is classified as a solid B.
What is the lowest passing grade?
In most secondary schools and undergraduate programs, the lowest passing grade is a D- or D (60.0%), which grants credit for elective courses. However, core major prerequisites, foundational sequences, and graduate courses typically mandate a minimum grade of C (70.0% to 73.0%) or C- (70.0%) to count toward degree completion.
How do teachers curve grades?
Teachers curve grades using mathematical formulas such as: (1) Flat Point Addition, adding a fixed number of bonus points to all students; (2) Highest Score Scaling, setting the top student score to 100% and multiplying other scores by 100 / top_score; or (3) Square Root Curving, setting curved score = √(raw score) × 10 to give larger relative boosts to lower scores.
What is a 7-point grading scale?
A 7-point grading scale is a stricter academic scale where an A requires 93% to 100%, a B is 85% to 92%, a C is 77% to 84%, a D is 70% to 76%, and any score below 70% is an F (failing).
Is a D a passing grade?
Yes, a D (60% to 69%) is technically a passing grade conferring course credit at most high schools and colleges, but it yields only 1.0 GPA points and often does not satisfy prerequisite advancement requirements for higher-level courses.
What percentage is an A minus?
On the standard North American collegiate scale, an A- (A minus) encompasses scores between 90.0% and 92.9%, granting 3.7 quality grade points on a 4.0 GPA scale.
How do I make my own grading scale?
To create a custom grading scale, specify your desired minimum percentage thresholds for each letter grade in descending order (e.g. A ≥ 92%, B ≥ 82%, C ≥ 72%, D ≥ 62%, F < 62%), ensure thresholds do not overlap, and generate a points conversion chart based on your syllabus total assignment weights.