How to calculate grades
Most syllabi describe categories (homework, labs, exams) each worth a percentage of 100%. Your running grade is a weighted average.
Weighted average formula
If assessment i has score sᵢ and weight wᵢ, the composite is Σ(sᵢ·wᵢ) ÷ Σ(wᵢ). When weights already sum to 100, this matches treating each score as a percent contribution.
Letters vs percents
Convert letters to representative percents (often the midpoint of the letter band) if you need a single numeric average—your instructor’s curve may differ.
Worked example (syllabus weights)
Homework 20% at 90, midterm 30% at 78, final 50% still ahead: running grade so far is (0.20×90 + 0.30×78) ÷ 0.50 = 82.8% if you only average completed weight. The final-grade calculator solves the missing 50% for a target such as 85%.
Connect class grades to GPA
Once the syllabus average becomes a letter, that letter maps to quality points on the 4.0 scale. Use the grade or weighted-grade calculator during the term, then drop the resulting letter into the GPA workspace to see the cumulative effect.