Ideal size for my root partition while having a separate home partition?

I only have a 480GB SSD for my whole Gentoo system. Do you guys have suggestions as to how big my root partition should be? I don't plan on installing a lot of packages, and I'm going to use a minimal window manager - won't be using something like Kde or Gnome. I've seen people recommending the root partition to be something around 30-60GB, what do you think?