Standard US Letter Grade Scale
The standard letter grade scale at most US colleges and public high schools assigns A through F in percentage bands per major letter tier. Plus and minus modifiers split each band into three sub-bands. The grade chart below covers all 13 letter grades from A+ to F with their percentage ranges, 4.0 GPA equivalents, and academic standing tier.
| Letter Grade | Percentage | 4.0 GPA | Standing |
|---|---|---|---|
| A+ | 97 - 100% | 4.0* | Excellent |
| A | 93 - 96% | 4.0 | Excellent |
| A- | 90 - 92% | 3.7 | Excellent |
| B+ | 87 - 89% | 3.3 | Good |
| B | 83 - 86% | 3.0 | Good |
| B- | 80 - 82% | 2.7 | Good |
| C+ | 77 - 79% | 2.3 | Average |
| C | 73 - 76% | 2.0 | Average |
| C- | 70 - 72% | 1.7 | Average |
| D+ | 67 - 69% | 1.3 | Below average |
| D | 63 - 66% | 1.0 | Below average |
| D- | 60 - 62% | 0.7 | Below average |
| F | Below 60% | 0.0 | Failing |
* A+ GPA = 4.0 at most US colleges; a minority award 4.3 on an extended scale.
This band structure groups each letter tier into Excellent (A), Good (B), Average (C), Below Average (D), and Failing (F). Each tier splits into three sub-bands via plus and minus modifiers: the plus sits at the top (87-89 for B+), the bare letter in the middle (83-86 for B), and the minus at the bottom (80-82 for B-). Only A+ deviates; on the standard scale it maps to the same 4.0 as A rather than a higher value. Source: NCES grade-distribution surveys and College Board grade-conversion guidance.
4.0 Grading Scale and GPA Conversion
The 4.0 grading scale converts every letter grade into a numeric quality-point value: A = 4.0, A- = 3.7, B+ = 3.3, B = 3.0, and so on down to F = 0.0. GPA is the credit-weighted average of those values across all courses on a transcript. This 4.0 framework underlies the American GPA system that US colleges report on transcripts. See the GPA calculator for the full formula with a live calculation.
4 Point Scale Grading System
The 4 point scale grading system treats every letter grade as a value from 0 to 4, with A as the ceiling at 4.0. Each plus or minus modifier shifts the value by 0.3 points (B+ = 3.3, B- = 2.7). The National Center for Education Statistics recognizes the 4.0 scale as the dominant standard across US institutions, though individual schools publish their own variants.
A Plus Grades on the 4.0 Scale
A plus grades (A+) are handled inconsistently across US institutions. At most colleges A+ carries the same 4.0 value as A: the plus shows on the transcript but does not raise the GPA ceiling. At schools using a 4.3 scale, A+ is worth 4.3 quality points, which allows a semester GPA above 4.0 when a student earns A+ in multiple courses. The 4.3 scale is more common at selective private colleges; most state universities stick to the 4.0 ceiling. Check the registrar's grading policy to confirm which version your school uses before planning for a GPA above 4.0.
5.0 Grading Scale: Weighted GPA for Honors and AP
The 5.0 grading scale is the weighted variant most US high schools use to account for the increased difficulty of Honors, AP, and IB coursework. A standard course A still earns 4.0, but an AP course A earns 5.0. A Honors course A typically earns 4.5. The chart above visualizes all five letter tiers across the three course types. The 1.0 bonus for AP and the 0.5 bonus for Honors are the most common amounts; verify the exact figures with your school, because some districts use different increments.
| Letter | Standard (4.0) | Honors (+0.5) | AP / IB (+1.0) |
|---|---|---|---|
| A | 4.0 | 4.5 | 5.0 |
| B | 3.0 | 3.5 | 4.0 |
| C | 2.0 | 2.5 | 3.0 |
| D | 1.0 | 1.5 | 2.0 |
| F | 0.0 | 0.0 | 0.0 |
The weighted GPA can rise above 4.0, which is why college admissions offices almost always recalculate to the unweighted 4.0 scale for cross-school comparison. A student with a weighted 4.4 and a student at a school that does not weight may both have the same underlying academic record. Use the GPA scale reference for the full 4.0 and 5.0 scale tables.
College Grading Scale vs High School Grading Scale
The college grading scale and high school grading scale share the same 10-percentage-point letter bands, but differ in two meaningful ways. First, most colleges use only the unweighted 4.0 scale: the Honors and AP bonuses from high school do not carry over to college courses. Second, college passing thresholds for major requirements are higher. A student who earned D grades in high school and passed every course may find that the same D grade in a college prerequisite does not satisfy the requirement for the next course in the sequence.
College grades on the standard scale work identically to the table above: A = 4.0, B = 3.0, C = 2.0, D = 1.0, F = 0.0 with plus and minus modifiers at 0.3-point intervals. Most students transferring from high school see a 0.3 to 0.7 GPA drop when the weighted high school figure is recalculated to the unweighted 4.0 college scale.
C Grade on Both Scales
A C grade is 73 to 76 percent on the standard US grading scale, worth 2.0 quality points. It is considered average standing: above the failing threshold, below the B average most programs expect. In college, C is the most common grade cluster in introductory courses where students adjust to university-level work. C satisfies many general-education requirements but often does not count toward major credit, where the floor is typically C or C+.
Passing Grade in College for Major vs Elective Credit
The distinction between "passing a class" and "satisfying a requirement" is the most common grading scale question students miss. A D- (60 percent) passes the course and earns elective credit. A C (73 percent) is what most major requirements demand. Some science and engineering prerequisites require a B- (80 percent) or higher. Pass/fail courses use a separate threshold, usually C- (70 percent). Always confirm which minimum applies to the specific course you need for your program.
Grade Scale Variations: US Grading System and International Comparisons
The US grading system, also called the American grading system, uses the standard letter scale, but institution-level variants exist. A small number of private high schools and selective programs use a 7-point scale where A starts at 94 rather than 93. The teacher grading scale for an individual course may also differ from the institutional default when the instructor publishes a custom syllabus cutoff: a 90-point A in a course with a custom scale is not automatically the same as the registrar's standard A. Verify with the syllabus before each term.
North American Grading System
The north american grading system uses the A-through-F letter sequence with the 4.0 GPA framework in both the US and Canada, though Canadian universities often use numeric percentage thresholds directly rather than converting to letter grades for transcript purposes. Grades in USA schools almost always display the letter grade as the primary credential, with the underlying percentage available in the grade detail.
Grades in USA vs UK First-Class Honours
UK degree classifications do not map one-to-one with US letter grades. A UK first-class honours degree requires 70 percent or higher on the UK scale, which corresponds roughly to a US A (3.7 to 4.0 GPA). A UK upper second (2:1, 60 to 69 percent) maps to a US B range (3.0 to 3.7 GPA). A UK 70 percent is an A equivalent on the UK system, not the C- it would be on the standard US scale. International grade mapping requires understanding each country's native scale before applying conversion tables.
USA Grading System vs German and IB Grading Scale
German university grades run on a 1.0 (best) to 5.0 (worst) scale, the inverse direction of the US 4.0-to-0.0 range. A German 1.0 to 1.5 maps to a US A grade; a German 5.0 is a fail. The IB grading scale runs 1 to 7 per subject, where a 7 corresponds roughly to a US A and a 4 is the minimum passing grade for most IB diploma requirements.
Scaling Grade Based on Question Count
Converting a raw number-correct score to a percentage depends on the total question count. A grading scale out of 20 questions gives 5 percentage points per question; a 50-question test gives 2 points per question; a 60-question exam gives 1.67 points per question. Quick-reference charts below cover the most common question counts. Use the grade calculator for any count not listed here.
15 Question Grading Scale
Each missed question on a 15-question quiz costs 6.67 percentage points. Key cutoffs: 15/15 = 100% (A+), 14/15 = 93% (A), 13/15 = 87% (B+), 12/15 = 80% (B-), 11/15 = 73% (C), 10/15 = 67% (D+). The wide per-question spread makes every missed answer GPA-significant.
20 Point Grading Scale and 20-Question Tests
On a 20-point grading scale, each question or point is worth 5 percentage points. 20/20 = 100%, 19/20 = 95%, 18/20 = 90%, 17/20 = 85%, 16/20 = 80%, 15/20 = 75%, 14/20 = 70%. The clean 5-point increment makes letter grade shifts predictable: each additional missed answer drops the score by one full sub-band.
25 Question Grading Scale
On a 25-question grading scale, each question is worth 4 percentage points. 25/25 = 100% (A+), 24/25 = 96% (A), 23/25 = 92% (A-), 22/25 = 88% (B+), 21/25 = 84% (B), 20/25 = 80% (B-), 19/25 = 76% (C), 18/25 = 72% (C-). The 4-point increment aligns cleanly with plus and minus band boundaries on the standard scale.
Points Grading Scale vs Percentage Grading Scale
A points grading scale uses raw point totals: each assignment has a fixed point value, and the final grade is total earned divided by total possible. A percentage grading scale uses category weights (homework 20%, exams 60%, final 20%) and averages percentages within categories. Most college syllabi blend both: raw points within a category, percentage weights across categories. The grade calculator supports both modes.
The A-through-F letter scale itself has a specific origin. Mount Holyoke College introduced letter grades in 1887 using A, B, C, D, and E (with E as failing). Yale used numerical rankings as early as 1785. By the early 20th century the A-through-F system with F as the failing mark had become the national standard, replacing both numerical and descriptive grading systems at most US institutions.
- Verify the syllabus cutoffs first. Every course may publish its own grading scale. If the syllabus is silent, the standard letter scale applies at most US institutions.
- Track borderline scores carefully. A 92.4 that rounds up to A reads very differently on a transcript than a 92.4 that truncates to A-.
- Know your school's rounding policy. Some schools round at term end; others apply the letter cutoff to the raw decimal. Ask the registrar.
- Confirm the weighted bonus amount. Honors and AP bonuses are typically 0.5 and 1.0, but the exact amount varies by district and school.
Browse Every Letter Grade on the Standard US Scale
Each page below covers the percentage range, 4.0 GPA value, sibling letters, and academic standing for one specific letter on the standard US grading scale. The pages share a common structure so you can compare any two letters side by side, and every spoke links back to this hub for the full scale comparison.