calculating NPV when cash flows dont neccesarily dont come at uniform times?

hi,

i need help figuring out how to compute a NPV from a series of cash flows. the NPV function is set up so that every cash flow is received at the beggining or end of a period. how would i make it so it could be calculated with a cash flow received at time 1.7 or 2.3?

thanks

Using that formula, you can't set it up so that it recognizes payments coming in at various times. My suggestion would be to use a helper column with a PV function and then just some those cells.