Hi MyThirdParty, thanks for supporting <3
The "16x16", "32x32" and "64x64" wordings are the tile size on which the sprites are based, not the size of the sprites themselves!
In many game engines you can set a "tilesize" or something like that, here is where you set 16,32 or 48 based on your preference!
Hope this helped, in case I'm here ;)