depends on what camera you are refering to...
being that you are asking about an 18-55 i will assume it is the Canon EF-S lens that comes on the Rebel, Rebel XT and the 20D.
in this case, any lens on those three cameras would have a 1.6 multiplication factor to get the same FOV as the 35mm equiv. this is caused by the CMOS sensor being smaller than a 35mm piece of film.
therefore your 18-55mm lens would appear to be the same as a 28.8mm - 88mm lens.