The Elder Scrolls Online was the first game in the series to attempt to bring parts of all of Tamriel's provinces to life since the very first game, The Elder Scrolls: Arena. However, the in-game areas created for each installment in the series only represent a fraction of those areas' sizes in the lore, leading to drastically different scales between the games in the franchise.
As a result some of the biggest areas ever rendered for the series have represented some of the smallest areas of Tamriel, while entire provinces have been summed up over deceptively small in-game maps. Here's how the size of the entire world of The Elder Scrolls Online stands up to previous Elder Scrolls games.
Scale In The Elder Scrolls
While The Elder Scrolls Online includes areas from all nine of Tamriel's provinces, it does not create a large unbroken game world like Skyrim largely does. The Elder Scrolls Online also does not claim to represent the entirety of Tamriel, instead allowing players access to smaller areas of each province divided by loading screens.
Indeed, while Elder Scrolls games like Skyrim use tall mountains and unnecessarily winding roads to help create an illusion of greater scale, all of the areas represented in-game across the franchise are best understood as scaled-down metaphors of the areas from the lore. The scaling doesn't quite line up either - if the map of Tamriel is to scale, then the Imperial city at the heart of Cyrodiil would be around the size of a small country. Tamriel has no canonically established size, however, leaving its real scale to the imagination of the players.
This leads to vastly different scales and in-game world sizes across the different Elder Scrolls games. Riverwood, a tiny hamlet in The Elder Scrolls 5, is at least big enough to warrant having its own ruler - Lord Asgens - in The Elder Scrolls: Arena. It also means that some locations that exist in the lore simply aren't present in the same areas when represented in-game. The town of Nimalten can be found in the Rift in The Elder Scrolls Online, for example, but is nowhere to be seen in Skyrim.
World Size Vs. World Design
While the Elder Scrolls games since Morrowind have attempted to create unbroken worlds, the map of The Elder Scrolls Online is broken up into more than thirty separate areas. While new zones are constantly being added with new content like the Gates of Oblivion expansion, the total world size of The Elder Scrolls Online is roughly 400 kilometers squared, making it one of the biggest Elder Scrolls games to date.
In comparison, Skyrim's map is only around 37 kilometers squared. Skyrim is slightly smaller than The Elder Scrolls 4: Oblivion's Cyrodiil, at 41 kilometers squared, with another 10 kilometers added with the Shivering Isles DLC. However, these differences in size don't necessarily reflect how big each of these worlds feel. Skyrim made particular use of varying elevation and winding paths to make journeying through its world take longer, and to stop players from being able to see across the map easily. In contrast, the White-Gold Tower at the center of Oblivion's map often left players aware of just how small the world was despite that world being larger than Skyrim.
The same can be said for The Elder Scrolls 3: Morrowind. Vvardenfell is around half the size of Skyrim, coming in at 16 kilometers squared. However, the third game in the main series didn't half fast travel at all. With Cliff Racers and other dangerous beasts lurking around every corner, the world could feel far larger and more threatening than later games in the series.
Nonetheless, The Elder Scrolls Online is far, far larger than Morrowind, Oblivion, and Skyrim. The first two Elder Scrolls games, however, made far greater use of randomly generated landscapes. The Elder Scrolls: Arena was said to be a ginormous 9 million kilometers squared. However, when players walked between towns they would often find that the terrain appeared to be infinitely looping, making this very difficult to prove.
Because of this, it is The Elder Scrolls 2: Daggerfall that is generally accepted to be the largest game in the franchise, with a generated landscape that can grow up 161,600 kilometers squared, which is roughly the size of Tunisia. Other sources put its size at closer to 200,000 kilometers squared. Excluding Arena, Daggerfall is the only Elder Scrolls game to blow The Elder Scrolls Online's size out of the water. Unlike Skyrim, players of The Elder Scrolls 2 were not expected to get anywhere near to exploring all of the possible locations that could be found in the game.
The dungeons and quests in the second Elder Scrolls game are all also randomly generated, leaving the world far less polished than the one found in the other main installments of the franchise or The Elder Scrolls Online. Players can even run across generated dungeons and quests which are literally impossible to complete, showing that size really isn't everything when it comes to RPG world design.
The Elder Scrolls Online may not technically be the biggest world created for the series. However, it is the biggest world that doesn't generate any of its landscape or content procedurally, and which uses the same general design principles that have been series staples since Morrowind. Arena and Daggerfall have the potential to be larger if the player's exploration forces the games to generate more and more land, but the scale of those games' maps are in no way matched by the amount of unique, voice acted, and story-driven content than can be found in The Elder Scrolls Online.
With Todd Howard claiming at Brighton Digital 2020 that The Elder Scrolls 6 would have a larger world with more realistic towns and cities than previous games, it's possible that the next Elder Scrolls will have a far more realistically sized world than Skyrim or Oblivion. Even still, it's unlikely to match the impressive 400 kilometers squared that can be found in The Elder Scrolls Online.
The Elder Scrolls Online is available on PC, PS4, Stadia, and Xbox One.