How to use the class average calculator
- Paste the scores, separated by commas, spaces or new lines.
- Enter the points possible and a passing score. The passing score is your own cutoff in the same points.
- Read the class average, median, mode, range and standard deviation, and the number and share of scores at or above the cutoff.
- Use the distribution table to see how many scores fall in each tenth of the points, and export it as CSV if you need it.
Formula
mean = sum of scores / number of scores
median = middle score, or the average of the two middle scores
standard deviation (whole class) = sqrt(sum of squared distances from the mean / n)
standard deviation (sample) = the same with n - 1
pass rate = scores at or above the cutoff / n x 100
The distribution groups scores by share of points: 0% up to 10%, 10% up to 20% and so on, with the last group including 100%.
Twelve scores
The scores 88, 92, 75, 64, 59, 81, 97, 70, 66, 85, 92 and 78 add to 947, so the mean is 947 / 12 = 78.92. Sorted, the middle two are 78 and 81, so the median is 79.5. The mode is 92, which appears twice. The range is 97 - 59 = 38.
The standard deviation for the whole class is 11.81, and the sample version is 12.34. With a cutoff of 60, eleven scores pass, which is 91.67%. The distribution puts 1 score in the 50% group, 2 in 60%, 3 in 70%, 3 in 80% and 3 in 90% to 100%.
Mean, median and spread
The mean is pulled by very high or low scores, while the median is not, so a big gap between them suggests a skewed class. The standard deviation measures how far scores usually sit from the mean: a small value means scores are bunched together, and a large one means they are spread out.
Use the whole class version when your scores are every student you care about, and the sample version if they are a sample of a larger group.
Using the pass rate
The pass rate uses whatever cutoff you enter, so the page does not claim any standard. If the pass rate is lower than expected, see what a curve would do with the curve score calculator. For other statistics use the standard deviation calculator or the general average calculator.
Assumptions and limits
- Scores are numbers between 0 and the points possible. A score outside that range is reported as an error.
- All scores are weighted equally, and no weighting between assignments is applied.
- The mode is shown only when a score repeats. If every score is different, the page says there is no repeated score.
- The passing score is yours to choose. Nothing here reflects a school, state or national standard.
Frequently asked questions
How do you calculate a class average?
Add all the scores and divide by how many scores there are. For 12 scores adding to 947, the average is 78.92. The page also shows the median, which is the middle score.
What is the difference between mean and median?
The mean adds everything and divides by the count, so extreme scores pull it up or down. The median is the middle value when scores are sorted, and it is not affected by extremes.
Which standard deviation should I use?
Use the whole class value when your list is the entire group. Use the sample value when the list is a sample drawn from a bigger group, because dividing by n - 1 corrects for the sample being a little less spread out.
How is the pass rate calculated?
It is the number of scores at or above your cutoff divided by the number of scores, times 100. The cutoff is whatever you type in the passing score box.