dll files for qt exe applications are too big. What to do?

dll files for qt exe applications are too big. What to do?

I am learning Qt.
and nowadays i wrote a simple calculator program.
size of calculator less than 1MB.
But to run this program in other computers(Windows)
i need to copy with this file some dll files such as
* Qt5Cored.dll
* Qt5Guid.dll
* Qt5Widgets.dll
* Qt5Widgetsd.dll
* etc.
And total size of this dll files more than 300 MB.
So does it mean that every time when i write new program in qt/c++
i have to copy 300 MB files to destination computer? Is there another
correct way to do this?
I heard VLC, VirtualBox and some other programs use Qt.
But i checked Source folders of that applications,
the size of that application folders are not so big. And there are not all
of these dll files.
So how do they solve this?
So how