The examples and perspective in this article deal primarily with Europe and the United States and do not represent a worldwide view of the subject. (December 2017) (Learn how and when to remove this template message)
Grading in education is the process of applying standardized measurements of varying levels of achievement in a course. Grades can be assigned as letters (for example A through F), as a range (for example 1 to 6), as a percentage of a total number of questions answered correctly, or as a number out of a possible total (for example out of 20 or 100).
In some countries, all grades from all current classes are averaged to create a grade point average (GPA) for the marking period. The GPA is calculated by taking the number of grade points a student earned in a given period of time of middle school through high school. GPAs are also calculated for undergraduate and graduate students in most universities. The GPA can be used by potential employers or educational institutions to assess and compare applicants. A cumulative grade point average (CGPA) is a calculation of a student's total earned points divided by the possible number of points. This grading system calculates the average for all of his or her complete education career. Grade point averages can be unweighted (where all classes with the same number of credits have equal influence on the GPA) or weighted (where some classes are given more influence than others)..
Yale University historian George W. Pierson writes: "According to tradition the first grades issued at Yale (and possibly the first in the country) were given out in the year 1785, when President Ezra Stiles, after examining 58 Seniors, recorded in his diary that there were 'Twenty Optimi, sixteen second Optimi, twelve Inferiores (Boni), ten Pejores.'" Bob Marlin argues that the concept of grading students' work quantitatively was developed by a tutor named William Farish and first implemented by the University of Cambridge in 1792. That assertion has been questioned by Christopher Stray, who finds the evidence for Farish as the inventor of the numerical mark to be unpersuasive. Stray's article elucidates the complex relationship between the mode of examination (testing), in this case oral or written, and the varying philosophies of education these modes imply, to both the teacher and student. As a technology, grading both shapes and reflects many fundamental areas of educational theory and practice.
Most nations have individual grading systems unique to their own schools. However, several international standards for grading have arisen recently.
In the General Certificate of Secondary Education (GCSE) exam taken by secondary school students in England and Wales, grades generally range from 9 (highest) to 1 (lowest). However, in GCSE Science, Mathematics Statistics, and any Modern Foreign Language, there are two tiers (higher and foundation). In the higher tier, grades 9 to 4 can be achieved, while in the foundation tier, only grades 5 to 1 can be awarded. The new 9-1 qualifications saw some more subjects such as English language and English literature go 'tierless,' with the same paper covering all levels of demand. Generally, a 4 or above would be considered a pass and a 3 or below would be considered a fail by most institutions: for Mathematics and English Language and English Literature, and possibly Science, this would require a resit.
If an candidate does not score highly enough to get a grade 1, their results slip will have the letter U, or 'ungraded,' meaning a grade was not secured. Other letters such as X also exist in special circumstances.
In Wales, the grading is still from A* (highest) to G (lowest). U is a fail.
Most colleges and universities in the United States award letter grades A, B, C, D, or F for each class taken. These marks are then used to determine an overall Grade Point Average (GPA) from 1.0 to 4.0, which is calculated using a formula. The average GPA is 3.3 at private institutions, and 3.0 at public ones.
Over the past hundred years, various colleges, such as Evergreen State College and Hampshire College have begun to eschew grades. Ivy League university Brown University does not calculate grade-point averages, and all classes can be taken on a pass/fail basis. Additionally, several high schools have decided to forgo grades. A notable example is Saint Ann's School in Brooklyn, which was ranked by the Wall Street Journal as the number one high school in the country for having the highest percentage of graduating seniors enroll in Ivy League and several other highly selective colleges.
According to a study published in 2014, a one-point increase in high-school GPA translated to an 11.85% increase in annual earnings for men and 13.77% for women in the United States.
College and post-college students often wonder how much weight their GPA carries in future employment. In the various broadly defined professions as a whole, internships and work experience gained during one's time in college are easily the most important factors that employers consider. In order of importance, the remaining factors are choice of major, volunteering, choice of extracurricular activity, relevance of coursework, grade point average and the reputation of one's college. The relative importance of these factors do vary somewhat between professions, but in all of them, a graduate's GPA is relatively low on the list of factors that employers consider. There is also criticism about using grades as an indicator in employment. Armstrong (2012) claimed that the relationship between grades and job performance is low and becoming lower in recent studies.Grade inflation at American colleges over recent decades has also played a role in the devaluation of grades.
Different educational boards use different metrics in awarding grades to students, along with the marks obtained in most cases. For example, Kerala state board uses a linear scale; A+ for a mark over 90%, A for a mark between 80% and 90% and so on. 
In Nepal, grading systems are of two types. In SEE Board, the grade point is calculated on the basis of range of marks obtained by students. For instance; Two students who score 86 and 89 respectively out of 100 full marks, then they are both included under A grade. While in NEB (National Examination Board), the grade points are awarded according to the actual marks obtained by the student but not according to range. For calculating GPA, the average of ranges of marks obtained is taken in SEE while, only average of marks is taken in NEB. This process is irreversible in case of SEE if someone wants to convert GPA to Percentage.
The national CBSE uses "positional" grades to indicate a student's position with respect to the rest of their peers in that subject, and hence the cutoffs required to obtain a grade will differ with year and subject; however, the percentage of students receiving them will roughly be the same.
Ultimately, grade inflation has severe consequences. Not only does it make it difficult for employers to vet the caliber of an applicant, but it also misleads students, who often use their grades as benchmarks to help diagnose their strengths and weaknesses.