Total Hours calculated in Project/Services

I'm a heavy sub-service user who prefers breaking down professional service templates as I create them. Sub-services and detailed descriptions generate nicely formatted bullets and assist with milestone billing. Example how I create and add professional services to a project or blueprint:

[Phase] - [Service-Category] - [Professional Service] ServiceX (0 hours) - [Sub-Service] Component1 (8 hours) [Sub-Service] Component2 (8 hours) - [Sub-Service] Component3 (8 hours) - [Sub-Service] Component4 (8 hours)

I'd love to see the Total Hours calculated in real-time instead of manually adding as I go (32 hours in this example). Normally, I envision a ballpark amount of days to deploy a certain product or solution. The small indicator will flag whether I'm in the correct range, or immediately indicate an error on my part - I've estimated 5 days but somehow managed to only scope 21 hours.