custom map

[idontknow]

i wanna make a custom map for my forest, which is gonna be either a cave or dungeon dmap--the tileset (pure) comes w/ a custom map for an overworld, where there's squares that are each like 4 pixels wide (& 3 high) but i just can't seem how to adjust them for a cave/dungeon dmap type, since you can fit less screens in those dmaps & link's position cursor moves further when moving from screen to screen--how big should i make the squares for each room in such a dmap?

[Freedom]

cave maps are a half of an overworld map, there are custom maps for the levels in Swansong, you can copy one ot those and then alter it to your needs.

[Cloral]

As you noted, you can fit half as many horizontally. Thereby, you can reason that they're twice as wide. What you should do is take your grid for the overworld, and join each pair of rooms horizontally. So you would join 0 and 1, 2 and 3, 4 and 5, ...
That will give you a grid to work off of.