A letter grade is a single letter, typically A through F, assigned to represent how well a student performed in a course or on an assignment. The system dates back to 1897, when Mount Holyoke College designed the format still used across most American schools today. Each letter corresponds to a percentage range and a numerical point value, making it easy to calculate a grade point average (GPA) and compare academic performance across courses.
The Standard Letter Grade Scale
Most schools in the United States follow the same basic framework. An A represents the highest level of performance, while an F indicates a failing grade. Here’s how the letters typically map to percentage scores:
- A: 90 to 100 percent
- B: 80 to 89 percent
- C: 70 to 79 percent
- D: 60 to 69 percent
- F: 0 to 59 percent
You might notice that the scale skips the letter E. While early grading systems did include it, schools eventually dropped E and jumped straight to F, likely because “F” clearly signals “fail” in a way that “E” does not.
These percentage cutoffs are common but not universal. Some schools set the A threshold at 93 percent rather than 90, and a few use 65 as the passing mark instead of 60. Your school’s syllabus or grading policy will spell out the exact ranges that apply to you.
Plus and Minus Grades
Many middle schools, high schools, and colleges break each letter into finer increments using plus and minus modifiers. A student who earns an 88 might receive a B+, while a 72 could land as a C-. These modifiers do more than signal a higher or lower standing within a letter. They also shift the grade’s point value when calculating GPA.
On a common plus/minus scale, here’s what each grade is worth:
- A+: 4.3
- A: 4.0
- A-: 3.7
- B+: 3.3
- B: 3.0
- B-: 2.7
- C+: 2.3
- C: 2.0
- C-: 1.7
- D+: 1.3
- D: 1.0
- D-: 0.7
- F: 0.0
Not every school uses plus and minus grades, and some that do cap the top at 4.0 rather than awarding 4.3 for an A+. Check your institution’s grading policy to see which version applies.
How Letter Grades Become a GPA
Your GPA is a weighted average of all your letter grades, where each course’s grade is multiplied by the number of credit hours that course carries. A three-credit course has three times the impact on your GPA as a one-credit course.
To calculate it yourself, multiply each course’s grade point value by its credit hours, add those products together, then divide by the total number of credit hours. For example, if you earned an A (4.0) in a three-credit class and a B+ (3.3) in a four-credit class, the math looks like this: (4.0 × 3) + (3.3 × 4) = 25.2, divided by 7 total credits, giving you a GPA of 3.6.
Most schools use a 4.0 scale, meaning an A is the highest grade that counts toward GPA. A handful of institutions use a 4.3 scale that rewards an A+ with extra points. High schools sometimes add extra weight for honors or Advanced Placement courses, creating what’s called a weighted GPA that can exceed 4.0 even on a standard scale.
What Each Letter Grade Signals
Letter grades are shorthand, and their meaning shifts depending on context. In a classroom, a C technically means the student met the basic requirements of the course. In practice, though, expectations vary widely. Many college programs require a C or higher (2.0) to count a course toward a major, and some demand a B or better in prerequisite courses.
For college admissions, most competitive four-year universities look for cumulative GPAs in the 3.0 to 4.0 range. Scholarships often set minimum GPA thresholds as well. On the other end, a D is usually considered passing but may not satisfy degree requirements, and an F earns zero credit hours, meaning you’d need to retake the course.
Employers rarely ask about individual course grades, but GPA can matter for your first job out of school. Some entry-level programs and graduate schools set a 3.0 or 3.5 cutoff. After a few years of work experience, GPA fades in importance.
Alternatives to Letter Grades
Some schools are moving away from the traditional A-through-F model in favor of competency-based grading, sometimes called mastery-based or standards-based grading. Instead of averaging all your assignments into a single letter, this approach tracks whether you’ve demonstrated mastery of specific skills or concepts.
The differences are practical. In a traditional system, a low score on an early quiz can drag down your final grade even if you eventually learn the material. Averaging penalizes students who need more time. In a competency-based system, grades reflect your most recent performance, and you typically get multiple opportunities to demonstrate that you’ve mastered a concept. Earlier low scores don’t follow you.
Traditional grades also sometimes bundle in factors like participation, behavior, or extra credit, meaning two students with the same letter grade might have very different levels of actual understanding. Competency-based systems separate academic mastery from behavioral expectations, so a grade reflects only what you know and can do.
Pass/fail is another alternative you’ll encounter, especially in college electives or certain graduate programs. You either earn credit (pass) or you don’t (fail), with no impact on your GPA either way. This can be useful when you want to explore a subject outside your comfort zone without risking your GPA.
How Grades Are Calculated Within a Course
Your letter grade in a single course is almost always a weighted combination of different assignment categories. A typical college syllabus might weight exams at 40 percent, homework at 20 percent, a final project at 25 percent, and participation at 15 percent. Your scores in each category are combined according to those weights to produce an overall percentage, which then converts to a letter grade.
This means not all assignments are created equal. Bombing a homework set worth 5 percent of your grade barely moves the needle. Bombing a midterm worth 30 percent is much harder to recover from. Early in a semester, reviewing the syllabus to understand the weighting can help you prioritize your effort and know where you stand as the term progresses.