Have ordered 17 watches from Revain over the years: Casio, Timex, Ben Nevis, Fossil. ALL were the right size. This one was incorrect as it was measured diagonally across the two buttons on the front. Below it is written that it is impossible to measure with buttons! How to easily measure the size of a watch case To measure the size of a watch case, place a vernier caliper on one side on the opposite side of the case, just above or below the crown where the case diameter is smallest. . Measure the case from end to end down the center of the watch, excluding the crown and pushers.