There are three freeware utilities that can be downloaded from this link: http://www.ultracad.com/articles.htm <http://www.ultracad.com/articles.htm> The one called ULTRACLC will calculate capacitance for stripline and microstrip, which might point you in the right direction (although not EXACTLY what you asked for) Good Luck (and let us know if you find another one) Jack -----Original Message----- From: Craig Elison [mailto:[log in to unmask]] Sent: Friday, September 15, 2000 6:36 AM Subject: Trace to Trace capacitance Can anyone give me a formula for calculating trace to trace capacitance given trace width and pitch? Craig Lead Design Engineer TRI-C Design