You have a long column of data in column A and want to observe their distribution (histogram).
put some desired bucket size in D3 e.g. D3 = 2
C6 =$C5 + $D$3
drag the bottom-right corner of the C6 cell down, to the create the desired number of bucket ranges
In column D select the cells in front of the cells that are showing bucket boundaries
in the formula row which is a part of the excel toolbox type:
hit CTRL + SHIFT + Enter
This will choose the data as first argument and bucket ranges in second.