Loading Calculator...
Please wait a moment
Please wait a moment
Calculate the first quartile (Q1), second quartile/median (Q2), and third quartile (Q3) of your data set.
Quartiles divide sorted data into four equal parts. Each quartile represents 25% of the data.
We use the inclusive method (linear interpolation) to calculate quartile values at positions (n-1)×q + 1.
Different software and textbooks use various methods. The most common are: exclusive (Excel), inclusive (R default), and median-based. Results may vary slightly between methods.
Values below Q1 - 1.5×IQR or above Q3 + 1.5×IQR are typically considered outliers. This is the basis for box plot whisker calculations.