Free statistics calculators designed for data scientists. This outlier calculator:
This calculator examines a set of numbers and identifies data points which fall meaningfully outside the typical range of the distribution. Enter each data point as a separate value, separated by commas. Then hit calculate. The calculator will generate a list of points which are significantly outside the observed distribution.
Want to do more analysis? We have tools that will allow you to plot the distribution and generate a histogram. Even better, you can save your data from this calculator and reuse it on that web page! Or come back and use it to check your work later. Simply hit the "save data" button. It will save the data in your browser (not our server, it remains private to you). It will appear on the list of saved datasets below the data entry panel. To retrieve it, click the "load data" button next to it.
The outliers tagged by the outlier calculator are observations which are significantly away from the core of the distribution. In this case, we calculated the interquartile range (the gap between the 25th and 75th percentile) to measure the variation in the sample. An observation is tagged as an outlier if it is greater than a multiple (1.5) of the interquartile range above or below the boundariers of the interquartile range.
For example, assume you enter 20 data points as your observations and hit calculate. If the 25th percentile value was 5 and the 75th percentile was 15, the interquartile range would be calculated as 10. Using the logic of tagging points that are 1.5 x the distance of the interquartile range away from the upper and lower bound of the interquartile range, we designate anything above 30 (15 + 10 x 1.5 = 30) and below -10 (5 - 10 x 1.5 = -10) as outliers.
Can be comma separated or one line per data point; you can also cut and paste from Excel.
Saved in your browser; you can retrieve these and use them in other calculators on this site.
Need to pass an answer to a friend? It's easy to link and share the results of this calculator. Hit calculate - then simply cut and paste the url after hitting calculate - it will retain the values you enter so you can share them via email or social media.