Andi is correct. He has put forward some conventional meanings to do with physical distance. Another conventional meaning: "I can't balance the accounts!" "How far out are you?" "Far out" together, however, is also an adjective. See these clear definitions from Google: far out adjective 1. unconventional or avant-garde. "a far-out psychic technique" synonyms:unconventional, unorthodox, unusual, non-conformist, individual, individualistic,idiosyncratic, quirky, out of the ordinary; 2. (informal) excellent. "It's really far out!" You will see that very reliable dictionaries such as the Cambridge Learners' Dictionary corroborate these definitions.

Far out (slang) - cool, extreme Far our - strange, unsual

"How far out are you?" could have a couple of different meanings. It's possible you are standing on a ledge, for example the edge of a mountain, and someone is asking you if you are close to the edge. Another meaning could be that you are travelling, and you are being asked how far away you are from a particular point; "We'll be in London soon." "Oh good, how far out are you?" "About 10km." In addition, "far out" can mean