Paste a list of numbers and get mean, median, mode, quartiles, IQR, variance, standard deviation, outliers, and skew in one place.
Why do you ask for sample or population?
Because that choice changes the answer. Sample spread divides by n - 1 and population spread divides by n. A page that picks one silently is making a statistical decision for you. This page makes it explicit.
Why might the quartiles differ from Excel or another calculator?
Because quartiles have several conventions. This page uses the Tukey median-of-halves rule and says so on the page. Another tool may interpolate between points instead. The difference is not arithmetic error. It is a convention difference.
What counts as an outlier here?
Anything below Q1 - 1.5 x IQR or above Q3 + 1.5 x IQR. That is the standard box-plot rule. It is a flag for an unusual value, not automatic proof that the point is wrong and should be deleted.
What does a positive or negative skew mean?
Positive skew means the long tail is on the high-value side. Negative skew means the long tail is on the low-value side. A value near zero means the distribution is roughly symmetric on this measure.
How should I type my numbers?
Use commas, spaces, semicolons, or new lines, and you can mix them. Do not use a comma as a thousands separator. Type 1234, not 1,234, because a comma always splits values on this page.