It differs from baby to baby and then from tooth to tooth. DD1 would work on one stupid tooth for weeks before I could see anything, and then they took forever in coming all the way up. DD2 had a really bad day and then a bad night, and that was it for her first tooth, it only took a few days to come all the way. The 2nd one just appeared overnight.: Now she is working on her 3rd and we are all miserable, it has been like this for a week and still no sign of a tooth.