4 on Mac, you may need to do some pre-installation. Installation is so much easy, However, if you don’t know just follow the below procedures. But If you have downloaded the Preactivated version then certainly you have to Install that. If you have downloaded the portable version of TransMac, then their no need for you to Install that. Create a Bootable macOS Mojave USB Installer on Windows 10 If only you are using it to create a bootable USB without any other files 8 GB Flash Drive is totally fine.
Basically, the size of macOS Mojave is almost 6 GB, but if you are inserting init the Post Installation Files certainly you have to use the 16 GB USB Flash Drive.