There is no official unit for distance in Don't Starve Together (DST), in publication or in code. Hence, there are multiple distance measurements used in the fandom wiki. There are distance measurements based on the source code, such as 'unit' and 'metre', while others based on players interactable objects such as 'tile' and 'wall'.
Distance measurements[]
Unit - may ambiguously refer to other measurements, but generally for distance, Unit is the most factual term since there is no distance unit in publication or in code. The map coordinate system is based on this value; computations and source code are generally based on this numerical value. 1 unit = 1m
Metre - common abbreviation m, A measurement introduced that specifies the dimensionless 'unit' in the distance dimension. The British spelling is preferable over the American spelling of 'meter' since meter may also refer to the various gauges in Dont Starve. Metres can be visualised in game using walls, tiles, console commands or mods. 1m = 1 unit
Wall - refers to the length of a wall. The distance measurement generally refers to the straight edge but there may be ambiguity if walls are lined up on a straight edge or diagonally; the diagonal of a wall is 1.41 times that of its horizontal length. Horizontal length of a wall = 1m
Wilson holding a Pitchfork to make the tile size visible
Tile - refers to the length of a tile. Tiles show up as highlighted squares when a Pitchfork is wielded over any turf. Tiles form the grid that the landform is based on. The distance measurement generally refers to the straight edge but there may be ambiguity if tiles are lined up on a straight edge or diagonally; the diagonal of a tile is 1.41 times that of its horizontal length. There may also be ambiguity if the distance concept may be referring to the map tile, such as in the case of farming, the crop tile. Horizontal length of a tile = 4m
Screen - refers to the length of a screen. However, a screen is not well defined, and may refer to: the radius of a screen, which is half a screen; the diameter of a screen, which is a whole screen; the zoomed out vision, which upper limit may be the loading radius. A screen is likely to be between 15m and 80m.
Evaluation of the different distance measurements[]
Metre is the clearest measurement for distance, without any ambiguity in the absolute quantity or other game concept. Computations and source code are generally based on metre's equivalent numerical value and hence there is no conversion from the game underlying data. There is also less decimals involved compared to tiles.
Tile is more observable to beginner players. Measurements based on tile may be less accurate due to uncertainty by editors, or due to zealous attempts by editors to overwrite other distance measurements with inappropriate conversions.