Note the equation for flow and dp calculator 

FLOW= K√DP

Or

DP= k (FLOW) ²

In percentage calculation we don’t need the factor k ,so we can avoid the factor k when we are calculating flow%  or  Dp% .

So  in our calculations, we use equation as

 FLOW= √DP

  DP=  (FLOW) ²

 ^{See the below article  to know more about flow and DP calculations}