Those numbers do seem more intuitive, but they can have some counter-intuitive consequences. So why not just say that a B is anything between 83.33 and 86.67? Those numbers seem more intuitive, as thresholds, than 83.5 and 86.5.No-the grades available in a grading system don’t need to be equally spaced along whatever numerical scales (e.g., grade points or percentages) they can be correlated with.

Does that mean there’s something fishy about the fact that pluses and minuses are worth only 0.3 instead of 0.33?.

If the grade points were more evenly spaced (e.g., 3.00, 3.33, 3.67, etc.), then the mathematical technique used above (the one used to fill in table 6) would yield more equally sized percentage-point ranges for the letter grades. But it reflects the fact that the grade points aren't themselves evenly spaced: there's a difference of 0.3 between some pairs of consecutive grade points (e.g., 3.0 and 3.3), but a difference of 0.4 between some others (e.g., 3.3 and 3.7).

The ranges for the plus/minus grades (such as B+ and B–) are 3.5 percentage points wide, but the ranges for the flat grades (such as B) are only 3 percentage points wide.

So, the minimum value for an A would remain 93.5, and anything above that (up to 100, or higher, for that matter) would still be an A: A third option, my preferred one, is just to absorb the values associated with A+ into the range for A. I think that would make A’s harder to get than they should be. This, however, would make the unavailability of the A+ grade result in a disproportionately high percentage required in order to get an A. But that would violate a lot of the constraints I’ve operated with so far, as well as being a mess.Ī second option is to proportionally enlarge the intervals associated with A and A–, so that 90 remains the minimum value for A–, with 95 being the new minimum value for A. One way of handling this is to enlarge the intervals associated with each of the eleven remaining passing grades (A down to D–). KU’s grading system, however, maxes out at A there is no A+. So that’s the way I would assign letter grades, under a complete plus/minus system. That means that I can completely fill in the “minimum percentage” table I started with, but couldn’t get very far with at the time (table 3): Table 8: So, these thresholds are actually the minimum percentages for the grades just above them. Second, should a student whose percentage is equal to a threshold percentage get the letter grade just above it, or just below? For reasons of charity, I prefer to award the letter grade just above it. Filling in the other values analogously, I have the following: By similar reasoning (working with 3.7 grade points for an A–), the middle percentage for an A– should be a 92. So, that should be the middle percentage for a B+. Since a B+ is worth 3.3 grade points, and 3.3 is 30 percent of the way from a B (3.0) to an A (4.0), I want to know what number is 30 percent of the way from an 85 to a 95. Now, to fill in the other percentages using KU’s grade-point conversion scale, I’ll assume that the relative spacing of the grades on KU’s grade-point conversion scale should dictate the relative spacing of the grades’ middle percentages on my grading scale. I’ll keep these as the middle percentages in my new grading scale: Table 5: My old grading scale had 95 in the middle of the A range, 85 in the middle of the B range, and so on. So, to use KU’s grade-point conversion scale to figure out my new percentage-based grading scale, I need to pay attention to middle percentages, not minimum percentages. The former were concerned with minimum values, and the latter is concerned with middle values (e.g., 3 grade points goes with the middle of the B range-it has nothing to do with the bottom of the B range). Notice, though, that there is a structural mismatch between tables 1–3 and table 4. (For now I’ll assume the possibility of A+, even though it is not an available grade at KU, and then I’ll adjust for its absence at the end.) Table 2: With the introduction of pluses and minuses, minimum percentages need to be determined for a much longer list of grades, as shown in table 2. For example, I usually used the following grading scale: Table 1:

When the only grades were A, B, C, D, and F, it was pretty easy to come up with a final grade calculator, and it was easy for me to show students how to calculate grade percentage. (Such grades had been available in some schools at KU previously, but not in the College.) Here are the web pages stating the KU and CLAS grade lists: In the Fall 2008 semester, the College of Liberal Arts and Sciences added grades with pluses and minuses (A–, B+, etc.) to its list of available grades.

Average percentage calculator