What would you change the title of this topic to? the new calulator is not my favourite, but the old one works for me best, and I build most big ships in one turn!
I always use the build-in windows calcm usually my ships need two retrofits until they are ready though. Like the "hull" can be build in 2 turns, and two more are spent for retrofitting, so they will be ready after 4 turns, given enough repair capability.