Five Number Summary Calculator
Calculate the five-number summary of a data set: minimum, Q1, median, Q3, and maximum.
Calculate the five-number summary of a data set: minimum, Q1, median, Q3, and maximum.
How Five Number Summary Calculator Works
These five values give a compact snapshot of a data set's shape and spread at a glance — the minimum and maximum mark the extremes, the median marks the center, and Q1/Q3 mark the boundaries of the middle 50%. This is also exactly the set of values used to draw a box plot.
Who Uses Five Number Summary Calculator and Why
- Getting a quick, compact snapshot of a data set's shape and spread before deciding on further analysis.
- Gathering the exact values needed to draw a box plot for a report or presentation.
- Comparing the overall spread and center of several data sets side by side using a consistent, simple set of numbers.
Mistakes to Avoid
- Expecting the five-number summary to identify outliers directly — it gives you the raw building blocks (including Q1 and Q3), but you need the separate 1.5×IQR rule (as in the Outlier Calculator) to actually flag specific outlier values.
- Computing the summary on unsorted data — every one of the five values (minimum, Q1, median, Q3, maximum) depends on the data being correctly sorted first.
- Treating the minimum and maximum as reliable descriptions of "typical" data — they're the most outlier-sensitive of the five values, unlike Q1, median, and Q3.
Tips for Best Results
- This is exactly the set of values used to construct a box plot — the box spans Q1 to Q3, the line inside marks the median, and the whiskers typically extend toward the min and max.
- If you specifically need to flag outliers rather than just summarize spread, follow up with the Outlier Calculator, which builds directly on Q1 and Q3.
Fixing Common Problems
My minimum or maximum looks like it could be an outlier, but the summary doesn't say so. — The five-number summary just reports the extremes as-is; it doesn't judge whether they're statistical outliers. Run those same values through the Outlier Calculator's 1.5×IQR fence test to check specifically.
Terms Explained
Five-number summary: A compact description of a data set consisting of the minimum, first quartile (Q1), median, third quartile (Q3), and maximum.
Box plot: A visual chart directly built from the five-number summary, with a box spanning Q1 to Q3 and whiskers extending toward the extremes.