Difference between THUS And HENCE

hence= from now on/from this point forwards
thus=therefore/in this way

Hence and thus are by common usage interchangeable, however according to the rules of grammar they are different.

Hence should indicate future use (Eg. Hence we will proceed as described)

Thus should indicate the past in its usage, or to indicate a conclusion (Eg. The British and American troops fought to a standstill, thus no winner was declared)