Weighted average and the grade you need on your final exam
Two questions come up every exam season: what is my average with the weights, and what do I need on the final? Both take one line to work out.
Weighted average
Each grade counts according to its weight (coefficient or credits):
Average = Σ (grade × weight) ÷ Σ weights
| Course | Grade /20 | Weight | Grade × weight |
|---|---|---|---|
| Maths | 14 | 2 | 28 |
| English | 11.5 | 1 | 11.5 |
| Economics | 16 | 3 | 48 |
| History | 9 | 1 | 9 |
| Total | 7 | 96.5 |
Average: 96.5 ÷ 7 = 13.79 / 20 (68.9%). The plain average of the four grades would be 12.63: the heavy weight of economics pulls it up.
The grade you need on the final
If the final counts for a share of your overall grade (its weight):
Final grade = current grade × (1 − weight) + exam × weight
Solve for the exam score:
Exam needed = (target − current × (1 − weight)) ÷ weight
Example: you have 55% so far, the final is worth 60%, and you want 60% overall. Exam needed = (60 − 55 × 0.4) ÷ 0.6 = 63.3%. To just reach 50%, you need 46.7%.
What the result tells you
- Above 100%: the target is out of reach, aim lower.
- Below 0: you already have it, even with zero on the final.
- The heavier the final, the more it can move your grade.
Try it
Paste your grades and weights into the weighted average calculator, then use the final exam grade calculator. For US-style grades, see the GPA calculator; for European universities, ECTS credits and year average.
Frequently asked questions
How do I calculate a weighted average?
Multiply each grade by its weight, add the results, and divide by the sum of the weights.
What do I need on my final exam?
Exam needed = (target − current grade × (1 − weight)) ÷ weight. With 55%, a final worth 60% and a 60% target, you need 63.3%.
What is the difference between a simple and a weighted average?
A simple average gives every grade the same importance. A weighted average gives more importance to grades with a higher weight.
This information is for guidance only and does not replace professional advice.