Calculated Fields

Vertabelo is great but it's missing Computed Columns feature, at least in SQL Server projects.

So Calculated Columns are created like this (Inventory), and I really think that implementing this feature for you is not a big trouble.

CREATE TABLE dbo.Products
(  
    ProductID int IDENTITY (1,1) NOT NULL  
  , QtyAvailable smallint  
  , UnitPrice money  
  , InventoryValue AS QtyAvailable * UnitPrice  
);

Full documentation on https://msdn.microsoft.com/en-us/library/ms188300.aspx