This information comes from the Apple press release for macOS Mojave, where Apple says the following:
“macOS Mojave will be available this fall as a free software update for Macs introduced in mid-2012 or later, plus 2010 and 2012 Mac Pro models with recommended Metal-capable graphics cards.”
From a system requirements standpoint, macOS Mojave appears to require a modern CPU as well as a GPU that is compatible with Metal graphics architecture. RAM may be less of an important element, though Mac OS tends to run best with more memory. In terms of disk space, typically you need storage for the installer, along with free disk space to install the update itself.
MacBook Pro (mid 2012 and newer)
MacBook Air (mid 2012 and newer)
MacBook (early 2015 and later)
iMac (late 2012 or newer)
iMac Pro (2017 or newer)
Mac Pro (late 2013 or newer, or mid 2010 and mid 2012 models with Metal capable GPU)
Mac Mini (late 2012 or newer)
http://osxdaily.com/2018/06/05/macos-mojave-compatible-macs-list/
Če sistem ni uradno podprt in bi vseeno lahko delal pa še tale link
http://dosdude1.com/mojave/