Academic grading in North America varies from country to country and even within countries.

United States

The most commonly used index in the U.S. educational system uses five letter grades. Historically, the grades were A, B, C, D, and F—A being the highest and F, denoting failure, the lowest. In the mid-twentieth century, many American educational institutions—especially in the Midwest (particularly the State of Michigan)—began to use the letters A, B, C, D, and E. The only difference here is that failure is denoted by E instead of F, which is not used by these schools. By comparison, the grade E is sometimes used in Canada as a conditional failing grade. No grades awarded on American quality indices are conditional, except special grades like I (Incomplete) and Y (course on non-traditional calendar, assigned to regular term in which the student enrolled in the course).

The A–F (A–E) quality index is typically quantified by correlation to a five-point numerical scale as follows:

• A = 4.0
• B = 3.0
• C = 2.0
• D = 1.0
• F = 0.0

Chromatic variants, represented by + and −, are commonly used. They are most commonly quantified as x.3 and y.7, e.g., B = 3.0, so B+ = 3.3 and B− = 2.7). A few institutions use only a single midpoint between the major points on the scale; that is, they regard an A− as effectively the same grade as B+. In those cases, an AB replaces the options of A- and B+ and is quantified as 3.5; a BC replaces B− and C+, with a value of 2.5; and a CD replaces C−/D+, worth 1.5. This approach is unusual and is most notably typified by institutions in the state of Wisconsin.

The grade A+ is a novelty in American education. The minority of institutions that use it may quantify the grade as 4.3 or 4.5, but many of them quantify A+ as 4.0 on the theory that a 4.0 scale cannot go higher than 4.0. By convention, quantitative scales are called by the highest whole number, so there is—at least, conventionally—no such scale based on 4.3 or 4.5, but it is still a 4.0 or 4-point scale because the fraction is ignored in naming the scale. D- is also rarely found, under the assumption that anything less than a D is by definition failure.

American high schools and universities sometimes weight their GPAs.

In the late 1970s and early 1980s, many primary schools began to employ quasi-eccentric quality indices in which E, historically a failing grade, was recast to represent "Excellent." Similarly, the graduate business school at the University of Michigan awards the grade X to represent "Excellent." (Please see the section on the The E-S-N-U system.)

American high schools typically require a 1.0 grade point average to qualify to take a diploma. The industry standard for undergraduate institutions is a minimum 2.0 average. Most graduate schools have required a 3.0 grade point average since 1975 (the transition began two decades earlier), but some schools still have 2.75 as their pass standard. Some doctoral programmes do not have a formal pass standard. For example, the Michigan Doctorate, conferred by the Rackham School of Graduate Studies at the University of Michigan, is awarded solely on the basis of competence in research. It is unlikely, however, that the University of Michigan would retain a student who is doing work below 'B' quality, notwithstanding the grade point average is technically irrelevant to conferral of the degree.

American law schools are notoriously out of step with mainstream graduate-level education. Most of them still require no more than a 2.0 grade point average to qualify for the professional doctorate in law. A few require 2.3 or 2.5 for post-doctoral degrees, such as the American LL.M. or S.J.D. degrees. Law schools also typically continue to award the grade D whereas the industry standard is to eliminate it from the graduate-level quality index.

The Rackham School of Graduate Studies, for example, uses the following 9.0 scale:

• A+ = 9.0
• A = 8.0
• A− = 7.0

• B+ = 6.0
• B = 5.0
• B− = 4.0

• C+ = 3.0
• C = 2.0
• C− = 1.0

• F = 0.0

Apart from law schools, graduate schools in some states (California among them) continue to award the grade D in graduate school, despite having a 3.0 degree pass standard—measured against which a D (1.0) is normally considered superfluous, because even B− (2.7 or 2.5) is a failing grade in most graduate schools.

Canada

In the Canadian province of Ontario, another system is placed that replaces the A–F system. This system was instituted by the provincial government in around 2001 . It is very much the same as the A–F system but uses numbers instead of letters. It goes like this:

• Level 4 = A or excellent (exceeds provincial standard, 80–100%)
• Level 3 = B or good (meets provincial standard, 70–79%)
• Level 2 = C or average (approaches provincial standard, 60–69%)
• Level 1 = D or passing (well below provincial standard, 50–59%)
• Level R = F or failing (remedial action necessary, 0–49%)

The system also adopts the +s and −s of the A–F system. So a 4− is about equal to an A−. Some teachers may also attribute the +s and −s to the R, meaning that an R+ is an almost fail, and an R− meaning no work or work of inferior quality. Some teachers have been known to become overzealous and give students 5s for spectacular achievement and −1s for below what is possible. These are usually converted to 4+s and R−s on the report card. The students' marks in Canada are also weighed differently, the marks are divided in four categories, Knowledge, Thinking and Inquiry, Communication and Application. The categories are worth different amounts depending on the course. For example, a knowledge-heavy course such as math would have Knowledge worth more than Communication while an English class would be the opposite. Lastly, in secondary school, the categories are equal to around 70% with the exam and culminating performance task worth the other 30% of the mark. Also a student may not get lower than a 20% in a class as long as the student hands in work.

Percentage-based grading

In objective subjects such as mathematics, grades normally computed according to percentages such as class attendance, homework completion, and test averages. A weighted average of these variables is used to compute one percentage, which is the index from which grades are determined.

In subjective disciplines where essay exams and papers are more common, grades are sometimes represented numerically, other times with letter grades.

The specific conversion of percentages to letter grades varies according to the class. In classes with very difficult problem sets, it's not unheard of for the cutoff for passing to be 20%, and that for an A grade to be given at 50%.

Usually, though, primary and secondary schools use fixed systems. The traditional system is the "Tens System", written as (90/80/70/60). In other words, the lowest A (or A/B line) is at 90%, while the lowest D (or D/F line) is at 60%. In order either to set a higher standard or correct for grade inflation, however, some schools use the "Nines System" (92/83/74/65) or "Eights System" (either 93/85/77/70 or 94/86/78/70). However, the system employed may not actually affect grading, since difficulty of exam questions may be calibrated to the grading system; indeed, exams in a school using the Tens System are often more difficult than those in schools using the other systems.

The Tens System is used in Canada but the A–F system (or in the case of Ontario, the 0–4 system) values are different from those of the United States. It goes as follows:

• A = 90 or higher
• B = 80–89
• C = 70–79
• D = 60–69
• F = 0–59

The pluses and minuses are taken into account also, so a plus is closer to the higher end of the score or the minus is at the lower end of the score. The percentage system is not used in primary schools, as all marks shown on tests, assignments and on the report card are shown with the A–F or 0–4 system depending on province. Percentage may also be provided along with tests. In senior elementary or secondary schools, tests and assignments are provided with both the mark on the present system in the province and also with the percentage. On the report card, only the percentage is shown on the final mark.

Various rubrics exist for assigning pluses and minuses, usually assigning them to roughly the top and bottom third of a grade level, with the base grade (that is to say, the one that does not carry either a plus or minus sign) being widest if the number of points in the entire letter grade are not evenly divisible by three. For example, under the Tens System, the plus grades will most commonly end in 7, 8 or 9 while the minus grades will end in 0, 1 or 2, with the base grades ending in 3, 4, 5 or 6. In the Nines System the plus, base and minus bands are typically equal (spanning three points each) while plus and minus formats under the Eights System vary widely; often the base grade will consist of four points and the plus and minus grades will consist of two points each, but this is far from universal. If A+ is omitted (and it often will be if the institution does operate under the grade-point system), the A and A− grades may cover the same number of points (or the A will contain one more point if their sum is an odd number), or the A− range may not be larger than those of the plus and minus grades found elsewhere along the grading scale, and the A range will be twice a large as that of the other base grades.

Mexico

Academic grading in Mexico employs a scale from 0 to 10 to measure the students' scores. Since decimal scores are common, a scale from 0 to 100 is often used to remove the decimal point. The grades are:

• 100: Excellent.
• 90: Very good.
• 80: Good.
• 70: Average.
• 60: Passing threshold.
• 0-59: Failed.

Students who fail a subject have the option of taking an extraordinary test (examen extraordinario, often shortened to extra) that evaluates the contents of the entire period. Once the test is finished and the score is assessed, this score becomes the entire subject's score, thus giving slacking students a chance to pass their subjects. Those who fail the extraordinary test have 2 more chances to take it; if the last test is failed, the subject is marked as failed and pending, and depending on the school, the student might fail the entire year. As a result, the extraordinary tests often cause a lot of stress among students, because they have to study for the entire period often in a couple of weeks.

Some schools (particularly in higher levels of education) require a 70 to pass instead of the regular 60.

Grades are often absolute and not class-specific. It may be the case that the top of the class gets a final grade of 69. Curve-adjustment is rare. Grad-level students are usually expected to have grades of 80 or above to graduate. Students in honor roll are usually those with an overall GPA of 90 or more upon graduation, and some private universities will award them a "With Honors" diploma.