accurate measurement and documentation is important in many aspects of dermatology and dermatologic surgery. Lesional andexcisional dimensions are most often measured rounded to the nearest millimeter and recorded for proper insurance coding, clinical studies, and data-base entries. Most often, measurements are made with a millimeter ruler (ie, stainless steel or on a marking pen), or from estimates based on accumu-lated experience in the daily use of such measuring devises. At times there is some difficulty in obtaining precise measurements with such methods. There is a risk of rounding errors, especially when relatively broad lines made by a gentian violet skin-marking pen surrounding the lesion or excision site are incorporated in the measurement. These errors can be compounded when measuring both lesional and excisional dimension in cases where such measure-ments are considered important such as in the surgical treatment of primary cutaneous melanoma. In addition, meticulous computation and measurement aids careful tissue transfer reconstruction design, which is necessary for optimal success in most reparative procedures. Accurate measurement may also be important in surveillance and follow-up evaluation of size change of pigmented and other