How do you calculate the Quintile for every row in Excel?

Question

I'm trying to calculate the quintile for every row of a column in Excel.

The resulting value for each row in Excel should be 1, 2, 3, 4, or 5.

A value of one will be the top 20%, a value of 5 is the bottom 20%.

This is my current formula which SEEMS to work, but I'm curious to see if anyone has a better way, a UDF, or sees an error in my formula...

=ROUNDDOWN(RANK.AVG(A1,$A$1:$A$131,0)/((COUNT(A$1:A$131)+1)/5),0)+1

A1 through A131 has the values I'm placing in quintiles.

Thanks

Answer 1

Your suggested formula works for me......but I think there are several ways you could do this, e.g. use PERCENTILE function to get the breakpoints and then match against those with MATCH, i.e.

=MATCH(A1,PERCENTILE(A$1:A$131,{5,4,3,2,1}/5),-1)

In most cases that gives the same results as your formula but there might be some discrepancies around the boundaries

Answer 2

I liked the simplicity of =MATCH(A1,PERCENTILE(A$1:A$131,{5,4,3,2,1}/5),-1). I compared the results with a two step manual process that included: 1) calculate 4 percentiles for .2, .4. .6 .8 and 2) a combination of nested IF statements and ended up with the same result as =Match recommended formula in a same of 250 values.

I.E. STEP 1:

=PERCENTILE.INC($J$3:$J$257,0.2) -> Adjust 0.2 to 0.4; 0.6; 0.8 accordingly

STEP 2:

=IF(J3<=$AB$3,5,
 IF(J3<=$AB$4,4,
 IF(J3<=$AB$5,3,
 IF(J3<=$AB$6,2,
 1))))

Compare each value to the calculated =PERCENTILE.INC in STEP 1