Semester Grade Calculator
Compute the semester, or solve for the final.
The three weights must total 100.
How the math works
A semester grade built from two terms and a final is a three-slice weighted average:
semester = (term1 × w1 + term2 × w2 + final × wf) ÷ 100
Under the common 40/40/20 split, terms of 84 and 88 with a 79 final give 33.6 + 35.2 + 15.8 = 84.6. The final's small slice is why an off day on the exam only pulled this student a fraction of a point below their term average — and also why rescuing a bad semester with one great final is so hard.
Flip to solve mode and the same student asking for an 85 needs (85 − 68.8) ÷ 0.2 = 81.0 on the final: reachable, and now a concrete number to study toward. Ask for a 90 instead and the math returns 106.0 — above 100, honestly out of reach without extra credit. The general version of this question, for any remaining chunk of any course, lives in the grade needed calculator.
Questions
What formula does the semester grade use?
semester grade = (term1 x weight1 + term2 x weight2 + final x final weight) / 100. With terms of 84 and 88 and a 79 final under the common 40/40/20 split, that is 33.6 + 35.2 + 15.8 = 84.6.
Why do the weights have to total 100?
Because the three pieces are the whole semester. If your entered weights total anything else (beyond a 0.01 tolerance for decimal entry), the calculator stops and says so rather than producing a number that means nothing.
What does the solve-for-the-final mode do?
It inverts the same formula: needed = (target - (term1 x weight1 + term2 x weight2) / 100) / (final weight / 100). It reports above-100 results as not reachable and zero-or-below results as already secured, exactly like the final grade calculator.
My school uses different weights than 40/40/20. Can I change them?
Yes - all three weight boxes are editable, and 40/40/20 is only a common convention. Some schools run 45/45/10 or give quarters and exams other splits. Your syllabus or student handbook wins.
Can the final's weight be 0 in solve mode?
No. With no weight on the final, no score on it can move the semester grade, so there is nothing to solve for. The calculator says that plainly instead of dividing by zero.