Ok I found some references of 250 miles from Almalexia to Red mountain and a reference of Lilmoth to the sea ( 15 miles ) , but not in official stuff just in other crossreferencing forum discussions .
I checked the map in the Imperial Library and the distanced to match , but the map is completely different in shapes and proportions from the one done by Morcroft from Beyond Skyrim, wich its based on the actual game heightmaps .

Applying those to the Morcroft map then ...

by some comparative calculations .

each square of 2048x2048 , is quivalent to 250 x 250 miles, wich means that

250 miles = 3.74784 km


http://img203.imageshack.us/img203/889/hf7q.jpg

I guess this is still disapointing a bit if we want to consider that as a large continent that spans from Ices of an Over Norwey border to the Jungles subtropical places .

PErhaps a rescaled dimensioning based on actual climatic zones would see Tamriel to be 5 times that size and the distance between Mournhold and Almalexia be of at least 1250 miles .

In that way the Skyrim northern border woudl correspond to the coasts of Norway and the bottom Argonia to the Central Indian Deccan Plateau.

http://img842.imageshack.us/img842/4260/txxr.jpg

So what you think , do you agree on the 250 miles proportions from Mournhold to Red Mountain? Or instead is more correct the 5 times that distance scale?