How to find out what region a movie disc is?

The DVD player on my computer tells me when I’m out of region.
A DVD purchased from an American retailer will nearly always be Region 1.

This is interesting, I just bought a new laptop and when I tried to rip a dvd it told me I had to choose a region. Oddly enough though it would not allow me to choose Asia, it insisted I choose region 3 which on my map is South America. I swear my other laptop was set to Asia???

Anyhow what ^ said, your computer will tell you what region you should have selected.

It may be that the discs that don’t show any region number are region free.
I am not sure how you would prove that, though.

The Region Code is specified on the back of the individual DVD and Blu ray packaging and on the disc itself. It is shown with a globe that has a region number printed over it. Informal term meaning “playable in all regions”. Region 0 discs will play on any DVD player.