Class grade
Points: grade = points earned ÷ points possible × 100. Example: 152 out of 170 = 89.41%.
Weights: grade = (score × weight, added up) ÷ (the weights, added up). Dividing by the total of the weights, not by 100, scales weights that do not add up to 100. Example: 90 at 30% and 80 at 50% give (2,700 + 4,000) ÷ 80 = 83.75%.
Scores can be typed as a percent (92) or as points (46/50). In weights mode, points are turned into a percent first. In a category with several scores, points are added up (18/20 and 45/50 make 63/70, 90%); plain percents are averaged.
Drop the lowest: we try every choice of scores to drop and keep the one that leaves the highest grade, so the scores that help least are dropped. At least one score always stays.
Extra credit: in points mode it is added to the points earned, not to the points possible. In weights mode it is added to the grade as percentage points.
Final exam
Needed on the final = (target − current × (1 − w)) ÷ w, where w is the final’s weight as a decimal. Example: 85% now, final worth 20%, target 90%: (90 − 85 × 0.8) ÷ 0.2 = 110%. Above 100% means the target cannot be reached with the final alone; 0% or below means it is already secured. The grade after a final score is current × (1 − w) + final × w.
GPA
GPA = (grade points × credits, added up) ÷ total credits. Grade points: A+ 4, A 4, A- 3.7, B+ 3.3, B 3, B- 2.7, C+ 2.3, C 2, C- 1.7, D+ 1.3, D 1, D- 0.7, F 0 (A+ can be set to 4.3). Weighted GPA adds 0.5 for honors and 1.0 for college-level classes, never to an F. Cumulative GPA adds the grade points and credits of every term, plus any GPA and credits already earned. GPA needed next term = (target × (credits so far + next credits) − grade points so far) ÷ next credits.
Tests and the EZ grader
Test grade = (total − number wrong) ÷ total × 100. Example: 3 wrong out of 25 = 88%. The EZ grader chart lists every number wrong from 0 to the total, in steps of 1 or 0.5, rounds each percent half up to the chosen decimals, and gives the letter for the percent as printed.
Grading scales
A letter is the highest band whose lowest percent is at or below the score. With rounding on, the score is first rounded half up to a whole number, so 89.5 counts as 90. Every cut-off can be changed in each tool’s grading scale settings.
10-point scale
A 90 to 100; B 80 to 89.99; C 70 to 79.99; D 60 to 69.99; F 0 to 59.99.
7-point scale
A 93 to 100; B 85 to 92.99; C 77 to 84.99; D 70 to 76.99; F 0 to 69.99.
Plus/minus scale
A+ 97 to 100; A 93 to 96.99; A- 90 to 92.99; B+ 87 to 89.99; B 83 to 86.99; B- 80 to 82.99; C+ 77 to 79.99; C 73 to 76.99; C- 70 to 72.99; D+ 67 to 69.99; D 63 to 66.99; D- 60 to 62.99; F 0 to 59.99.
What this leaves out
- Curves, late penalties and teacher-specific rules. Your teacher’s gradebook is the final word.
- School-specific GPA rules such as grade replacement for retaken classes, or bonuses other than 0.5 and 1.0.
- Grading systems outside the US letter scale, such as UK degree classes or percentage-only systems.
How we check it
Automated tests check every formula above with worked numbers, including the edges: 89.5 with and without rounding, weights that do not add to 100, impossible and already-secured finals, half points and the share-link round trip. They run before every release.