I have this problem a lot, because the nature of medieval fantasy is that people travel quite a bit. As a fellow writer, to get around the problem of being accurate with maps/time and distances, I get around the problem by never putting a scale or mentioning distances in miles/km/leagues. Just decide that, on your map, two weeks' travel = x cm. The great thing about medieval fantasy is that in that sort of time period people don't have the world's best idea of distance - and everyone's distances are different (take the difference of london, bristol and york miles for instance). The 'universal measurement of distance' is time taken to travel. I have two major cities that are two weeks' travel by horse and I base all other measurements against this.

I have this problem a lot, because the nature of medieval fantasy is that people travel quite a bit. As a fellow writer, to get around the problem of being accurate with maps/time and distances, I get around the problem by never putting a scale or mentioning distances in miles/km/leagues. Just decide that, on your map, two weeks' travel = x cm. The great thing about medieval fantasy is that in that sort of time period people don't have the world's best idea of distance - and everyone's distances are different (take the difference of London, Bristol and York miles for instance). The 'universal measurement of distance' is time taken to travel. I have two major cities that are two weeks' travel by horse and I base all other measurements against this.