Criteria based calculation help.

Hello guys I currently have this formula together…

=($B$6*'Detail Service Calculator'!$AA$15-(SUM('Detail Service Calculator'!$S:$S,)))/($B$6*'Detail Service Calculator'!$AA$15)

What it does is calculate a percentage 99.95%
--
What I would like to do is keep this calculation, however, only perform this function if Colum X:X = 1. Not sure if this is possible because I tried the following…

=IF(COLUMNS(X:X)=1,B6*'Detail Service Calculator'!AA15-(SUM('Detail Service Calculator'!$S:$S,))/(B6*'Detail Service Calculator'!AA15),"")

But it gave me the following percentage which was wrong… 96163199.95%

Any help would be greatly appreciated. Thanks in advance!