I've never seen Andromeda, even when I was in a deep dark sky area and could remember where to look. This [1] NASA picture of the day shows, enhanced to be visible, just how big it actually is in the night sky.
I looked it up: it's 1/4 of a degree. The sun and moon are each 1/2 a degree.
So, Andromeda appears half (diameter) of the sun or moon.