How to Calculate a Weighted Average (Grades and More)

Credit-weighted grade averages, midterm and final weightings, and how they differ from a simple average, with step-by-step examples.

At the end of term you may see an average on your transcript that is not what you expected. The usual reason is that grades are not weighted equally but by the credits of each course. Once you understand weighted averages, you can check both your grade point average and any midterm-and-final calculation yourself.

How it differs from a simple average

For a simple average you add the grades and divide by how many there are. The simple average of 90, 70 and 80 is 80. For a weighted average, you multiply each grade by a weight (credits, a percentage share and so on), add the products, and divide by the sum of the weights.

An example with credits

Say you have three courses: Maths, 6 credits, grade 90; History, 2 credits, grade 70; Physics, 4 credits, grade 80.

90 × 6 = 540
70 × 2 = 140
80 × 4 = 320

The products total 1,000 and the credits total 12. The weighted average is 1,000 ÷ 12 = 83.33. The simple average is 80, but the weighted one is higher because your best grade was in the course with the most credits. It works the other way too: a high grade in a low-credit course barely moves the average.

Midterm and final weightings

Many courses weight a midterm at 40 percent and a final at 60 percent. With 50 in the midterm and 80 in the final, your course grade is 50 × 0.40 + 80 × 0.60 = 20 + 48 = 68. Weightings vary between schools and even between courses, so check the syllabus. Some courses also require a minimum score in the final.

Converting to other scales

Letter grades and 4.0 scales are converted differently by different institutions. If you need a conversion for a job or university application, use the official table from your school rather than a general rule.

Common mistakes

Forgetting the credits and taking a simple average.
Dividing by the wrong total instead of the sum of the weights.
Including pass/fail courses, which usually do not count toward the average.
Counting both attempts of a repeated course. Many schools use the latest grade, but check your own rules.

In the average calculator, write each grade and its weight on a line (for example "90 6"). It shows the weighted and simple averages together. There is also a separate calculator for midterm and final weightings.