Thank you Lars for your quick responds.  I found the issue - I created a WIP Custom Form and added there the calculated field, then attached this field to the report and to the project dashboard. Because the Custom Form is not attached to the Project the calculated field will not work there. 

I have created calculation field, which is based on the data from two different fields (which are also included in the Custom Form)  FormulaSUM({DE:Outcosts to date},{DE:Outcosts to complete}) Are attached the calculated field to one of the report and the report is attached to the project dashboard....