Backing up both windows and mac to one drive

I would like to know what is the best way or if there is a way to backup both my windows and mac with a single usb drive i currently have a WD element . Any formats that could do this or methods workarounds? any info in general would help.

exFAT is your best option, but the backup process will need to be done manually (Copy & paste) unless you are able to obtain an automatic backup program that supports exFAT.