Could any one assist this old duffer? I have successfully put together a fairly comprehensive circuit calculation spreadsheet in Excel for circuits up to and including 16mm2. However, can anyone advise how I can enter a cell instruction to convert Cos theta to the sine of the angle. For example power factor is 0.8 and sine of same angle is 0.6. All I want to do is enter 0.8 into a cell and the corresponding cell correctly inputs 0.6.