The answer is: a lot. If the base image is about 5Gb in ~/Downloads This will be copied to ~/.vagrant.d/boxes Then it will unpack to maybe 18Gb in ~/.vagrant.d/tmp vagrant up will cost you another 18Gb under ~/VirtualBox VMs That’s a total of 46Gb free space needed, because Vagrant doesn’t clean up as it goes. Tips: You can delete the original base image after provisioning Use a hard-drive space visualisation tool like GrandPerspective (Mac) or WinDirStat (Windows)