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.