The Eights System is the informal name for one of the three most common grading scales used at educational institutions in the United States. It has gained increasing popularity in recent years, largely in response to the phenomenon known as grade inflation.
The name refers to the fact that three of the four highest letter grades have a range of eight points, while the remaining one spans seven points. The distribution is uneven because with the minimum passing standard of 70% the system observes, there are 31 possible passing numerical grades — from 70 through 100, all inclusive.
There are two common variants of the Eights System in use, each one encountered with roughly equal frequency. One features the "D" grade as the one with only seven points in it, while in the other the "A" range is shortest.
The former variant is shown below:
93 to 100 = A
85 to 92 = B
77 to 84 = C
70 to 76 = D
Below 70 = F
The other variant is sometimes referred to as the "Sevens System" because the "A" grade is the one that contains only seven points:
94 to 100 = A
86 to 93 = B
78 to 85 = C
70 to 77 = D
Below 70 = F
As in other popular grading systems, a "+" or "−" modifier may be added to any of the letters (but customarily not to the "F") in order to draw a finer distinction. The most common means resorted to for this is to attach a "+" to the two highest of the eight possible numerical grades, a "−" to the two lowest, and no sign at all to the four in between (within the letter grade that has only seven possible numbers the middle three carry neither a "+" nor a "−"). However, this procedure is not implemented universally, and many permutations exist, such as rendering the top three of the eight points as part of the "+" grade, the bottom two as part of the "−" grade, with the middle three carrying no additional sign. In cases where the "F" grade is subdivided, "F+" will often represent 65 to 69, or sometimes 60 to 69 (in either format), and on occasion an "F−" will also exist.
Some schools do not assign the "A+" grade (in most cases the institution exercising this option issues grade point averages). Where "A+" is omitted, both its range and that of the "A" may be lumped together (as an "A"), or the two may be split evenly, with 97 to 100 constituting an "A" and 93 to 96 an "A−" if 93 is considered an "A−" rather than a "B+." If not — that is to say, the "Sevens System" alluded to above is employed — 94 to 96 will usually be classified "A−," creating greater symmetry across the entire grading scale since the "A" grade, encompassing only seven points, will have only two subdivisions, while the lower grades which contain eight points each are subdivided threefold.