The formula
Grade = Σ (weight × category average) ÷ Σ weightIf every category is graded and the weights add up to 100%, the bottom of the formula is just 100. If a category isn't graded yet, it's left out of both the top and the bottom, so you get your grade so far.
Worked example
- Homework: 20% × 95 = 19.0 points
- Quizzes: 30% × 82 = 24.6 points
- Tests: 50% × 76 = 38.0 points
- Total: 19.0 + 24.6 + 38.0 = 81.6%, a B- on the A+ to F scale
The plain average of 95, 82 and 76 is 84.3%, almost 3 points higher. The weighted grade is lower because the lowest average, tests, is worth half the grade.
With the final still to come
Say homework is 20% (95%), tests are 60% (80%) and the final exam is 20% but not taken yet. The grade so far is (20 × 95 + 60 × 80) ÷ 80 = 83.75%. To see what you need on that final, use the final grade calculator.
Common questions
- How do weighted grades work?
- Each category is worth a set percentage of your grade. Multiply each category average by its weight, add them up, and divide by the total weight. Homework at 95% worth 20%, quizzes at 82% worth 30% and tests at 76% worth 50% give 19 + 24.6 + 38 = 81.6%.
- What if my weights don't add up to 100%?
- That usually means a category, like the final exam, isn't graded yet. The calculator divides by the weight graded so far, which gives the grade your teacher's gradebook shows right now.
- Where do I find the weights?
- In your syllabus or course outline, or in your school's online gradebook, which often lists each category's weight.
- Why is my grade lower than my average score?
- Because the categories you scored lowest in are worth the most. A strong homework average can't make up for weaker tests if tests are half the grade.