It feels like Skyrim(the province) is bigger in the game than Cyrodiil was in OB. But on the map of tamriel cyrodiil is bigger than skyrim! That could either mean that tamriel has expanded a lot in two hundred years or that bethesda aren't relly sure how big tamriel is in the lore. I'm confused.

It's only due to the scale of the map.

The real Skyrim is much bigger than that in the game, the same goes to Cyrodiil. Only the scale of Cyrodiil is greater than that of Skyrim, so you feel Skyrim is bigger.

The games aren't the actual size of the province. They only show the things that are interesting for the player. No sense in having you walk through a hundred miles of grass lands just to go from one ruined fort to another ruined fort.

Edit: Ninja'd

Correct me if I am wrong. But I thought that Skyrim and Oblivon are around the same size. But because Skyrim has mountains it feels bigger. Don't forgot as well, Morrowind and cyrodiil are both quite big. But because Morrowind was set in Vvardenfell, it made it look like Vvardenfell alone was as big as cyrodiil, this has happened before.

Actually, in-game Skyrim and Cyrodiil are roughly the same size. Skyrim just has a larger amount of hilly and mountainous terrain, along with impassable terrain barriers.

Anyway, the in-game size of a province isn't reflective of how big the province really is in lore.

Tamriel is described as being 12 million square miles in the Arena manual. Making the entire map a grid, Skyrim equivalates to roughly 1,372,591 square miles in size and Cyrodiil to 2,283,121 square miles. This makes Cyrodiil about 1.66 times the size of Skyrim.

That makes Tamriel larger than the entirety of North America! It would be roughly the size of two Russia's. Somehow I thought the continent was much much smaller.

Breaking news: Gamedevs and writers have no sense of scale. More at eleven.

Meh, Tamriel's only a wee bit bigger than Africa according to that measurement. Though I do wonder if some of the distances we've been given match up with the Arena manual's sizing of Tamriel.