Calculated field showing Values as % of Grand Total of other desired column

[bhavikvc]

Hi Guys,
Not sure if this problem has been posted earlier or not, but here is what I wish to do.
I have attached a snapshot of the problem here...

Basically I want the LOSS Column to be seen as % of GRAND TOTAL of Order Column. And this has to be done using the CALCULATED FIELD function under the calculations tab

View image: Untitled

Your feedback is welcome.

Thanks