Average grade calculator

Add every grade together and divide the total by how many grades there are. Scores of 88, 92, 79, 95 and 84 sum to 438, and 438 ÷ 5 gives 87.6%. That method assumes each grade counts equally. Where assignments carry different shares of the final mark, a weighted average is needed and the plain arithmetic mean will be wrong.

An average grade treats every score as equally important, so a one-point quiz counts as much as a final exam. A weighted grade multiplies each score by the share of the course it represents before averaging. Use the unweighted mean when a syllabus says all assignments count the same, and a weighted average whenever it lists percentages per assessment category.

Removing the lowest score raises the mean, and the effect is larger the fewer grades there are. Dropping the lowest of 88, 92, 79, 95 and 84 removes the 79, leaving four grades that sum to 359 and average 89.75% instead of 87.6% — a rise of 2.15 points. With twenty grades rather than five, the same drop would move the average by a fraction of a point.

The median is the middle grade once the scores are sorted, or the average of the middle two when the count is even. Sorting 88, 92, 79, 95 and 84 gives 79, 84, 88, 92, 95, so the median is 88%. The median ignores how extreme the outliers are, so a mean far below the median signals that one or two poor scores are doing the damage.

Add every student’s final grade and divide by the number of students. The arithmetic is identical to averaging one student’s assignments — only the meaning of each entry changes. A class average of 87.6% across five students means the same computation as a personal average of 87.6% across five assignments, and the same caution about outliers applies.

Letter grades cannot be averaged as letters, because a letter covers a band rather than a point. Convert each to its percentage or its grade-point value first. Averaging an A and a C as grade points gives 4.0 and 2.0 for a mean of 3.0, a B — but averaging the underlying percentages of 95 and 75 gives 85, which is also a B, and the two routes do not always agree.

Rounding is set by institutional policy, not by the arithmetic. Many schools round to the nearest whole percent, so 89.5% becomes 90% and crosses into an A−, while others truncate and leave it a B+. A calculated average of 87.6% is reported here to two decimal places so the raw figure is visible before any rounding rule is applied.