: At least 12.5GB of available space for an upgrade from OS X El Capitan 10.11.5 or later; up to 18.5GB for earlier releases. A clean install requires at least 20GB.
To install macOS Catalina 10.15.7, your Mac must be compatible with the following hardware list: : Early 2015 or newer MacBook Air : Mid 2012 or newer MacBook Pro : Mid 2012 or newer Mac mini : Late 2012 or newer iMac : Late 2012 or newer iMac Pro : 2017 or newer Mac Pro : Late 2013 or newer General Technical Requirements: macos catalina 10157 installer upd
This is the easiest way to update if you are already running an earlier version of Catalina: macOS - How to Upgrade - Apple (SI) : At least 12
: Includes several important security fixes recommended for all users. System Requirements and Compatibility System Requirements and Compatibility : Minimum 4GB of
: Minimum 4GB of RAM (8GB recommended for optimal performance).