Here is a excel spread sheet, modified from Alex's spread sheet (http://www.sevenstring.org/threads/...for-7s-and-8s-it-does-fan-fretted-too.100074/) Changes and limitations Alex's, - continuous variation in gauge values are possible(to cover non-D'addario and new D'addario string gauges, e.g. 0.095) - As tension is calculated based on polynomial regression and data of D'addario strings, there would be errors. However, it should be better than none. - specifying wound/plain string is done by 'wound' column(wound=1 if wound, wound=1 otherwise) - tension in kg is added. Hope this helps.