Pivot Table - Calculated field. A change of source data layout required

Hi,

I need to compare cost by actual vs forecast vs budget. and thinking of using pivot table for comparison. That is how i created a data worksheet. from there, i create a pivot table. However, when i tried to use calculated field to calculate each variance, it cannot be done with i what had in mind based on my current layout in source data.

Can someone here look into my source data and comment how to change it in order to get the variance in 1) budget vs actual, 2) forecast vs actual in pivot table.

Thanks