How big is unreal engine in total?

the pc is my dads and he wants to know how big it is before i download it on his pc.

the actual engine, or what you download from the launcher, because those are different. the engines around 3-4gb, but from the launcher its a 15-20gb pacakge because of all the plugins and extras are also downloaded as well.

The package is about 15-20 gb.