what format will work for Mac and windows and handle an 8Gb to 20 Gb file?

I want to move my linux virtual machine's .vdi file from my Mac to my PC

It's a dropbox VM, and i'm pretty sure it will work on the PC, i just need a way to move it. I have a 16Gb USB and i've compressed the file down to 8 Gb in zip which seem to work on both Mac and PC. The USB is formatted to FAT 32 but it won't copy the file, i think because FAT32 can't handle files over 4Gb? what format do i need? and how do i reformat the USB on my Mac?