Weighted grade calculator

Your scores

Example

Score (%)Weight

Add a score

Weights are relative: use the percentages from your syllabus (homework 20, midterm 30…) or simple numbers (1, 2, 3).

Weighted average

84.42%

3 scores · total weight 60

On a common 90/80/70/60 scale that’s B. Your school or instructor may use a different scale - check the syllabus.

What do I need on the next one?

Goal95%90% (A)85%80% (B)75%70% (C)65%60% (D)Weight

With weight 40, you need at least 85.9% on the next assessment.

How is a weighted average calculated?

Multiply each score by its weight, add the results up and divide by the sum of the weights:

where $s_i$ are your scores and $w_i$ their weights. For example, 92% on homework (weight 20), 78% on the midterm (weight 25) and 85% on quizzes (weight 15) give $\frac{92 \cdot 20 + 78 \cdot 25 + 85 \cdot 15}{20 + 25 + 15} = \frac{5065}{60} \approx 84.42\%$.

Which weights should I use?

The ones from your syllabus. Courses usually list each part as a share of the final grade - homework 20%, midterm 25%, final exam 40% - so you can type those numbers straight in. Only the proportions matter: weights 20, 25 and 15 give the same average as 4, 5 and 3.

What do I need on the final?

Pick your goal and enter the weight of the next assessment. The calculator finds the lowest score that brings your weighted average up to the goal:

where $W$ is the total weight so far and $w$ is the weight of the next assessment. In the example above, reaching 85% with a final worth 40 takes at least 85.9% on the final.

Letter grades

Many schools use a 90/80/70/60 scale:

Average	Letter grade
90% and up	A
80–89.99%	B
70–79.99%	C
60–69.99%	D
below 60%	F

Your instructor may use plus and minus grades or a different scale, so treat the letter as a guide. The syllabus has the final word.