Basically it's ambiguous as a question.
Like for example, earlier I asked my mum "how far are you?" and because she's travelling to London today, she knew I meant "how far away from London are you?" was to be interpreted so she answered "we're near Portsmouth" but, I could've also meant "how far are you" as in "how far are you on Papa Pear Saga?" but depending on the conversation and situation, it's open to any interpretation.