Tip : Pentaho PRD : Calculated field in Pentaho Report Designer ( Calculate Percentage field)

Lets say sub1, sub2, sub3 are the query fields . To calculate Percentage on these 3 fields use below formula in

1) Drag and drop number field PRD palette (from left side).
2) Click on + button to write formula in expression editor and write formula as follows.
Formula :
=(([sub1]+[sub2]+[sub3])/300)*100