Linear Breakdown (Excel)

Fri, 15 May 2026 13:00:00 +0100

“I’m not such a big fan of having a linear answer to things.” [Adam Driver]

Abstract

How can you break down annual data such as:

to monthly data which is piece-wise linear:

In cells A2:B5 you enter your annual input data. In cells A8:A56 you enter the chronological month ends. For a start you can enter into B8: =B2/12. In B9 you enter =VLOOKUP(DATE(YEAR($A9)-1,12,31),A$8:B8,2)+(MONTH($A9))*(VLOOKUP(YEAR($A9),$A$2:$B$5,2)-VLOOKUP(DATE(YEAR($A9)-1,12,31),A$8:B8,2)*12)/(12*(12+1)/2) and copy down. In D8 enter =STDEV(B9:B56) In case you need EXACT numbers rounded to the cent, preserving the original sum, enter into C9 =ROUND(B9,2) and into D10 =ROUND(SUM(B$9:B10),2)-SUM(C$9:C9) and copy down. This is just a pragmatic rounding method without VBA. If you like to perform this correctly, look up RoundToSum.

Linear Breakdown of Annual Data to Monthly Data on Sulprobil

Linear Breakdown (Excel)

Abstract