How to Use QUARTILE.EXC in Excel

QUARTILE.EXC finds Q1 and Q3 the way most statistics packages do. Learn when to choose it and how it differs from INC.

You will learn to

• Find Q1 with QUARTILE.EXC
• Find Q3 of another measure
• Compute the quartile coefficient of dispersion

How it works

QUARTILE.EXC calculates quartiles using the “exclusive” method: the first quartile sits at position (n+1)/4 in the sorted data, rather than INC’s 1+(n−1)/4. On small samples this pushes Q1 lower and Q3 higher, giving a wider interquartile range. It matches the default in many statistics packages and textbooks, so use it when your numbers must agree with them.

QUARTILE.EXC only accepts quart values 1, 2 and 3 — the minimum and maximum (0 and 4) return #NUM!, because a sample can’t tell you the population’s true extremes.

=QUARTILE.EXC(B2:B13,1)