IP address/public forum

[SurreyGuy]

If I'm using a works PC to post on a public forum (yes, work DO know before anyone berates me!), what info pertaining to my location can the administrators of the forum glean from my IP address? Will they simply be able to find out which country I'm in or can they narrow my location down further?

Also, will all the PCs in our company have the same IP address?