How to use the drop lowest score grade calculator
- List each category with its weight, how many of its lowest scores are dropped, and its scores.
- Write scores as points (18/20) or as a percent out of 100 (85). Separate scores with commas or spaces.
- Choose whether a category average is the total points or the mean of percents, and add any extra credit in the advanced options.
- Read the course grade with the drops and without them, which scores were dropped, and the grade of each category.
Formula
score percent = points earned / points possible
drop the lowest scores by percent (the earlier score goes first on a tie)
category average = kept points / kept possible, or the mean of the kept percents
course grade = sum(weight x category average) / sum(weight)
Categories with no scores, or a weight of 0, are left out and the remaining weights are scaled to fill the grade. Extra credit is added to the final percentage.
Homework, quizzes and exams
Homework is worth 30 percent with scores 18/20, 9/20, 20/20, 17/20 and 16/20, and the lowest one is dropped. Quizzes are 30 percent with 8/10, 6/10, 9/10 and 10/10 and the lowest dropped. Exams are 40 percent with 82 and 90 and nothing dropped.
Homework drops 9/20 and rises from 80.00 to 88.75 percent. Quizzes drop 6/10 and rise from 82.50 to 90.00 percent. Exams stay at 86.00 percent. The course grade is 0.30 x 88.75 + 0.30 x 90 + 0.40 x 86 = 88.03 percent, compared with 83.15 percent with no drops, a gain of 4.88 points.
How ties and uneven point values work
The lowest score is the one with the lowest percentage, not the fewest points. When two scores tie, the earlier one in your list is dropped first. With the total-points method, a dropped 1/2 and a dropped 9/10 affect the category differently from the mean-of-percents method, because a big assignment counts for more in total points. Your syllabus decides which applies, so try both.
You cannot drop every score in a category: the number dropped must be smaller than the number of scores.
Using the result
The comparison with no drops shows how much the policy helps. To find what you need on a remaining exam, use the grade calculator. For the spread of a set of scores see the class average calculator, and for a different policy that weights recent work more, try the decaying average grade calculator. Your GPA turns final course grades into a term average.
Assumptions and limits
- Every score has points possible above 0. A plain number counts as out of 100.
- The weights you enter are the real weights in your course. They do not need to add to 100, but they are scaled to.
- Extra credit is added as percentage points to the final percentage, not to a category.
- The tool applies the rules written above. It is an estimate, and your instructor's record decides.
Frequently asked questions
Does a dropped score still count as attempted?
It is removed from the calculation completely. If your course counts missing work as zero before dropping, enter the zero as a score so that it can be the one dropped.
Can I drop more than one score?
Yes. Set the drop count to the number of lowest scores that your course removes in that category. The page lists every dropped score so you can check it.
Why do the two average methods differ?
With total points, large assignments carry more weight. With the mean of percents, every assignment counts the same. They agree when every assignment is worth the same number of points.
What if a category has no scores yet?
It is left out and the other weights are scaled up, so the grade reflects only what has been graded. The page tells you which categories it skipped.